Bloodhound Missile Preservation Group


The Bloodhound MKII missile system was a key part of the integrated UK air defences during the Cold War, a wholly British designed defensive weapon to counter nuclear armed, high flying bombers at long range.

Bloodhound MKII became operational with the RAF in 1964 and continued to be improved as new technology became available with its operational role continually enhanced to include the countering of low level air strikes. 

The missile system was withdrawn from RAF service in 1991, at the end of the Cold War. It is only right that such an important part of the UK's Cold War history is preserved for future generations.


BMPG's restored Bloodhound MKII Simulator in operation.

Bloodhound MKII Missile with Radar Type 87 in the Background at Menzingen BL64 Museum, Switzerland

Key News

06 Jun 2016 Four BMPG videos published on YouTube  Click  Never seen in public before; a unique insight into this Cold War system.

19 Sep 2015 We can say that we switch on, the simulator boots, and runs perfectly every time. Three years and two months after we pulled it out of the long grass and nettles by we can say we are there.

The Bloodhound MKII missile system was a key part of the integrated UK air defences during the Cold War, a wholly British designed defensive weapon to counter nuclear armed, high flying bombers at long range.

Bloodhound MKII became operational with the RAF in 1964 and continued to be improved as new technology became available with its operational role continually enhanced to include the countering of low level air strikes. 

The missile system was withdrawn from RAF service in 1991, at the end of the Cold War. It is only right that such an important part of the UK's Cold War history is preserved for future generations.


Jul 16
The sim was run up after a break of two weeks and pleased to say it remains serviceable.

The LCP cabin restoration continues! Quite a gang of us today as besides Neil and myself there was Richard V plus Dave S and his brother-in-law John. Neil and Richard had an inspiring day scraping paint of the end wall of the LCP cabin; a definite 'mind in neutral' job. Dave and John spent a fair bit of time battling to remove the awning spreaders from the LCP roof. After doing battle with rusted bolts and their castellated nuts retained with rusted split pins it was decided that the complete bracket assembly for each spreader would be unbolted from the cabin roof to make life easier for all. The spreaders can then be restored at a later date while the main effort remains on the main cabin. I spent time on corrosion treatment of screw heads and priming the cable duct housings of the left hand wall of the cabin. The housings are fibreglass so a special 'plastic' primer is being used - only available in black!

Jun 25
On arrival today the Argus wouldn’t boot. As soon as data started to be transferred from the CF card (disk) to the ME148 Store (memory) the parity LED on the ME148 lit and nothing else happened. A reseating of the ME148 and a clean of the edge connector made no difference. The ME148 that had now failed was the LCP spare used to replace the original ME148 which had also gone U/S. The original ME148 was still in the LCP. An observation; a lot of the faults we have with the A700 boards tend to be on units with mother and daughter combinations. – Store, GL and GX processors. It was therefore worth a go at the previously removed and U/S ME148, I cleaned the edge connector and then unscrewed the daughter board and easing it out before reseating it back on the mother board. I then put the original ME148 in the A700, switched on and all ‘S’ again. The simulator ran for a good period with no further problem. I now have the removed, original LCP spare, ME148 at home and I’ll give it the same treatment and see if it works OK in the test rig. The reson for the failures became evident when it was realised that the aperutures left by removal of air vents for cleaning and paint preparation had been covered with polythene to prevent ingress of vermin; unfortuantely this also stopped ingress of air causing condensation to form due to adverse humidity conditions ... lessons learned!

Off-site work has included the thrilling task of cleaning external rubber connector covers. Some good quality tyre paint will hopefully restore the rubber and cover the green paint which has been randomly sprayed over the covers during in-service repainting.

Jun 04
The simulator is now ‘S’ again. An ME153 GL processor was used from the test rig to replace the U/S ME153.

Plenty of scraping and painting was had with Neil removing more of the residue of the top coat on the rear wall of the LCP cabin. I attacked the cable access panels on the right hand wall. Wire brushed and cleaned with sugar soap solution. All ready for painting.Neil and I put our heads together regarding the position of the LCP and could we leave the axles on the cabin? With apologies to our wood fettler Ian, Neil set about dismantling a large pallet to provide 3 metre lengths as shims to sit on top of the wooden sleepers. Giving an extra 1 cm of clearance allows us to leave the axles on the cabin and the wheels are clear of the floor. The plan is to move the LCP out from its current position to near the hangar doors, better light, better for paint drying etc. We then push it back when we pack up for the day.

Tried a software dump to tape in the LCP as Neil has now set MEZ’s and No Light zone configured. A box of old and used DC600A tapes were checked over this wee; almost all are unusable. The belts were stretched, snapped in use, had shiny sections where they rested on spindles and the tape itself, probably not used sine 1991, a key missing part. Amongst the tapes were sets labelled:- Swiss Dump 4A Issue 2- Bloodhound ADP- Bloodhound SZ Developer Tape (marked 'Faulty')For a few minutes I thought the developer tapes were for the UK software but under the faulty labels I could make out 'SZ'. All the tapes on these cassettes have stretched, split or broken drive belts (see photo), some tapes had 'sticky' tape which stuck to itself. Symptoms due to storage for many years in poor conditions. I'll short cut all the testing of tapes that I have done and get to a sort of resolution. In the box of tapes were some DC6250 tapes, not compatible with the A700 so I've used the belts from those on the DC600A tapes. The DC6250 belts are a bit smaller than DC600A or the DC6150 belts but as they are stretched they work with these tapes absolutely A OK and are a good firm fit. If necessary I can exchange the DC6250 belts with any cassette that has belt problems. The ¼" tape cassettes we use have one big weakness their belts and you can't buy spares! I'm now thinking about our tape reliability as I did for the original A700 disk. Is there a solid state replacement? What I do know is that there is no SCSI to QIC-02 solid state emulator so it's not an option to replace the tape drive. The tape drive though is not the problem, it's the cassettes. What I am now thinking is; is it possible to copy all the utility/test programs to disk (CF card) on the A700? If this can be done then A700 formatted CF cards can be copied to create as many backups we need. The supplier of SCSICFDISK (Peripheral Vision) has PC software that copies CF cards no matter their format or what is on them. Perhaps Gustav can advise if copying a number of utilities to disk is possible. There is a tape with a disk image for test programs but is it the same?The ex-eBay G5 120A power supply (RIFA capacitors changed) has now been in use on the test rig for a good number of hours and remains ‘S’. We therefore have a spare in the LCP and of course a G5 120A on the test rig.

An initial batch of paint has been ordered: Etch primer, Matt NATO Green, MV primer (Ferrous materials), Black tyre paint and Fibreglass/plastic primer.

May 28
First task was to get the LCP/Simulator serviceable again. On refitting the two ME153's from the test rig in the workshopg both indicated as U/S when booting up. The  two ME153's, that were U/S unit from last week now worked again ..... everything burst in to life. Ran the LCP for a while, no problems. Also ran the Sim at the end of the day and it fired up OK and was left in a 'S' state. Not sure what was going on, dirty backplane connector - perhaps.

Back to the paint scraping for Neil who was full of admiration for the new hot air guns that worked a treat. He did take care not to melt holes in the side of the LCP but he did manage to burn a hole in his hand instead. I fussed around paint scraping the covers for the door vents, easy peasy with the new heat guns, they also needed a bit of metal bashing to get them back in to their correct shape; door vents and covers now temporarily refitted. I also rubbed down the large cable duct cover ready for a repaint.

We have an ME168 Hand-Held Monitor ... but there is an operator problem, I have no idea how to use it to test an ME153. Perhaps there is an ex-Ferranti out there who could advise us.

Finally, discussed with Neil that we should treat, prime, paint and then refit the roof catches ASAP so time to buy some paint. We also discussed what not to paint so features on the cabin stand out. No, I'm not suggesting picking out features in red. Thoughts on this is welcome. I know the LCP cabin was just sprayed all over with little thought for detail but I think we can do a better job than just spraying everything.

U/S ME147 (1Mb memory card) now at the workshop; Pete M removed this faulty card a few months back re parity errors. I'll investigate how to repair.

I had two extra T86 door keys cut last week and they were checked yesterday. All three T86 door keys now work so Neil and I have one plus the spare (original) is labelled and in the drawer of the LCP tool cupboard. The padlock has now been removed from the T86 door which is securely locked by the door handle. All down to great work on the door mechanism.

May 21
The dirty bit first as work continued on removing loose paint from under the T86 cabin and the cable ducts on the right hand side of the LCP cabin. The ducts now need a good clean before repainting, they are engrained with dirt. Neil was the dirtiest after his work on the underside of the T86 cabin; he also discovered that a box section that runs under the door frame was completely rotten on the underside, a job for the future though. The original plan was to finish the paint scrapping on the rear wall of the cabin but unfortunately one hot air gun was totally dead with a blown filament and the second gun only produced enough warm air enough to dry my hair [he doesn't have any Ed.] but totally useless at removing paint. I’ll sort out a couple of hot air guns this week, one being a replacement for Pete M’s gun.

Some bad news in that the simulator has gone U/S. one of the ME153 GL processors has failed. I’ll bring along the two spare ME153’s we have next Saturday and get the simulator running again. We now have at least three U/S ME153’s so I’ll be looking at how these can be repaired as a priority.

As Neil said when we left, ‘we broke more that we fixed today’.

May 14
Neil and I spent a considerable amount of time under the T86. It was a case of ‘let’s see how bad it is’ and once you start you tend to carry on. In fact the condition of the underside of the T86 was better than expected with a few corrosion patches but mostly flaking paintwork and dirt. We did find a rusted box section under the radar door. It looks very much that the repainting of the underside had been a cursory affair with a spray over what could be seen by not actually going under the cabin. I suspect nothing was cleaned prior to a respray, hence all the loose paint. Neil and I probably cleaned about 25% of the underside, Neil also removed rusty bolts that previously secured the flooring.

The new T86 door key was used to lock and unlock the cabin door. Thanks go to Dave for his work on the door mechanism and lock. We now have a complete set of LCP and T86 keys and door locks that work – yippee. Thanks to Nils in Sweden for sending us a copy of the Swedish radar door key, apparently the only thing he kept from his days with the radar.

I turned my attention back to the LCP cabin. One job to do was remove the remains of the keyring and lanyard attachment from all the plugs and sockets one the left hand side of the LCP cabin. This done it was a wire brush job to clean off the rusty screw heads before treating them with Kurust. The keyrings and lanyards that secure the rubber plug and socket covers will be replaced once repainting is completed.The refurbished fittings for the LCP roof catches were returned; these are zinc coated steel castings, nuts and bolts are stainless. Unfortunately coated steel spring washers were used on the main (long) securing bolts which have corroded over time and in many cases caused corrosion to eat away at the zinc coating on the catches. Before being primed the corrosion on the catches was treated with Kurust.

The LCP door vents had also been cleaned, rust treated and primed before being returned.

In working under the T86 cabin it was noticed that the trailer steering linkage had been disassembled at some time and not fully reinstalled. The main securing bolt had its nut on by only a few threads; how long had it been like that? The wiring for the trailer lights has braided wire sheath which in many places is completely corroded through. We are looking at completely removing the wiring and its sheathing to allow for a cabin repaint. All can be replaced after a repaint as the braided wire sheath can still be obtained.…and finally.

The simulator was run up and checked. No problems and it remains serviceable.

May 07
Dave has done a tremendous job on fixing the T86 door lock and mechanism which was completely seized after years left exposed to the elements when in storage as the door was left open! The T86 door can now be closed and locked ... if we could find the key which highlighted a problem. That is we keep losing things and I include myself in this.

After a bit of initial paint scraping by yours truly Pete M arrived and after the usual cup of tea we discussed how to repair the damage to the skin of the LCP cabin. Options discussed mainly revolved around how best to pull the panels out and flat etc. and what was practical and/or possible. Where the skin of the cabin has been bent, creased or distorted and in one place holed is mainly due to the ‘U’ channel framing on to which the panels are riveted being bent. After some discussion re options we decided that we had to remove one section of creased skin to see what we were up against as ‘pulling it out’ would not restore the original flatness or shape of the U channel frame or panel . Thanks to Dave having his multi cutter Pete M removed a damaged section of skin, an area that had been holed as it would need patching anyway, so we could better asses what we were up against. The attached photos show this process. First conclusion: To restore the shape of a bent U channel frame section (forget the skin for now) would require removing the skin in the area of the damage and then involve a good deal of force to pull out the bent section of frame. You will see in photo 3 how the section of U channel frame has not only been bent inwards but the bottom of the channel rolled over on itself. Pete M designed a pulling system for the channel from materials we found in the hangar, the pulling force being provided by a car jack. This system worked well in pulling out the bent section of the frame but the ‘rolled over’ damage to the frame is another matter for consideration. My thinking on repairing the skin is to fit flush ‘invisible’ patches riveted to supporting sections under the skin. Any thoughts or input on these repairs is welcome.

Apr 16
At the start of the day the simulator was run up - all OK and serviceable.
It was then getting on with the non-glamorous task of paint stripping the LCP. Most of the LCP paint had been removed previously but the tricky bits of the riveted lap joints and roof catches are now being attacked. The time is approaching when the underside of the T86 needs wire brushing - any volunteers?

Apr 09
Not much work was done on the previous two Saturdays as we had a man down with flue then visitors.
LCP status: as previously reported the LCP had gone U/S a few weeks back when a G6 60Amp PS failed and so did the spare when it was plugged in! Original PS now repaired and also the spare which has been soak tested. Cause of the failures were the usual RIFA capacitors in the spare and bead tantalum capacitors. All RIFA and bead tants replaced on these two PS’s. The spare G6 60A is back in the LCP. We are aware that we don’t have a spare G5 120A in the LCP but a couple need testing and the caps changed.

This Saturday the LCP was fired up and the simulator ran, no problems. Once the sim was given a run through it was switched off as the work on Saturday was focused on the LCP cabin. We made a start on paint stripping and cleaning the rivet lap joints and roof catches, the main panels were stripped last year. The plan is:
1. Remove all paint from the LCP cabin for a repaint this summer.
2. Prep the rear of the T86 Ae assembly for a repaint.
3. Wire brush the underside of the T86 chassis for a red lead and paint job – any volunteers for this one?

The objective is to get the LCP and T86 in a presentable condition as the expectation is that there will be an equipment move towards the end of the year.

Mar 14
Not a lot to report in that we carried on cleaning and scraping down the rear of the T86 aerial system and Neil did battle with the radar floor.

The LCP is still U/S after the failure of a G6 60 Amp PS. We have three spare G6 60 Amp power supplies so not a problem to replace the faulty unit – I thought. Firstly the spare in the LCP failed after a few seconds and when I checked the other two spares at home, they were also U/S. The workshop spares were brand new units, one gave a puff of smoke and the other just didn’t do anything. Out of four dead power supplies it should be possible to get one running for next Saturday. Usual capacitors are suspect; these spares hadn’t been soak tested previously.

Feb 27 It was cold in the hangar on Saturday but anyone called Pete is allowed to stay in the nice warm LCP!!! On this principle Neil has now changed his middle name to Pete (according to Dave). OK, Neil did do some good work (while sat in a warm LCP) as he had worked out the MEZ for the Bloodhound force in the UK from data originally supplied by Richard which Neil transposed to give MEZ coordinates on to the E.C’s P display. Neil also set up the correct ‘No Light’ bearings to reflect Yellow section at Bawdsey. 

Dave spent the day continuing to dismantle the T86 door lock and mechanism, not an easy task as the whole assembly is solid with corrosion etc. All securing screws having to be drilled out, except one, which Dave was pleased about!
I spent the day making a start on the rear of the Ae Assembly, scraping and dismantling ready for a clean and re paint (sometime this coming summer). It’s a sort of priority task as once the aerials are removed we won’t be able to get at the rear of the assembly.

And finally .... the LCP is U/S! Not a serious problem, PSU7 (a 6V 60 Amp PS) in the computer rack failed towards the end of the day. Not a problem as there was a spare in the LCP. Unfortunately the spare PS lasted a few seconds before also failing. I am sure this is a PS age problem rather than something causing them to fail. The spare would have had a quick check before going to the LCP, obviously it needed a proper soak test! I’ll have a go a repairing the power supplies, we also have a few more spare 6V, 60 Amp units so we should all be back to normal next time we are on site.

Feb 25  New Year Summary - Pete Harry
Firstly I want to thank everyone who has made a donation to the BMPG. Without such support we would struggle to fund many of the tasks in returning the LCP and T86 to their 'in service' condition. I give you anexample; all the chrome drawer handles and latches etc in the LCP needed rechroming, a task that has been completed at a cost of £1,100. Donations made it happen. Every penny we receive is spent on the restoration and no where else! If you are able to donate our bank details are:
 Acct Name: BMPG Limited
 Sort Code 30-18-83
 Acct No. 13392468
Cheques can be made payable to, 'BMPG Limited' and sent to: Pete Harry 7 Pinkham Cleobury Mortimer Kidderminster DY14 8QE.  BMPG Ltd is our legal entity and a 'not for profit company'.

Now back to the restoration news: The winter tends to be a quiet time asregards restoration of the LCP and T86, the main reason being 'who wants to workfreezing cold conditions at  this time of year'. That said the restoration team arenow getting back in to the swing of regular Saturday working at the site.

The LCPThe computer system, I/O racks and the displays are now fully restored,continue to run reliably. Work on the LCP will now be directed towards its appearance and the plan is to repaint the cabin by the end of the coming summer. Pete M is currently putting together a few videos on the LCPand the simulator which will help with a public awareness of what we areachieving.

The T86 rotten plywood and lino floor of the T86 has now been removed. The condition of the floor was poor due to water ingress during the T86's many years in store in the open, or should I say, abandoned in the open. Neil, Dave S and Ian  are the main workforce tackling the T86 floor and now have a temporary one fitted. All the chrome drawer handles have been removed in the T86 for re chroming and work is starting on the rear of the aerial assembly for restoration,cleaning and re painting.

Jan 30
1. The LCP had some difficulty waking after it's break. The FT81 displayed errors indicating failure to load the operational software, which we diagnosed as a defective ME147 Store Card (upper 'parity fail' LED lit). After replacing ME147 card # 401 with ME148 #136, the system ran perfectly all day.

2. While Neil, Dave and Ian did hard graft on the radar, Pete M hid in the nice warm LCP gathering material for our proposed YouTube videos.

3. Today's achievements were:
a) Temporary floor installed in the radar
b) Loads of photos taken and videos recorded.
c) Fire / Test switch, red cover lock removed for offsite fettling by Dave S.
d) Various other radar parts cleaned and lubricated.
e) Eight filled donuts consumed.

Dec 12
1. Yesterday was dominated by a lot of physical labour by Neil and Dave with the T86. Work continues on the flooring, removing the hard-to-get-at bits which includes under the drawer unit and the Tx cabinet. Didn't get to the flooring under the Tx as the drawer unit was enough of a challenge. Anyway, drawer unit and flooring removed from under it. All the chrome handles have now been removed from the T86 equipment racks and have been replaced with bits of rope. You have to be able to pull on something! A T86 man was also asked to drag up memories from 37 years ago on how to release the runners for the equipment draws in the Tx rack.

2. CHARGE was a problem when we first switched on the LCP but that was resolved with some edge connector cleaning and the Ferranti representative (Pete M) letting us know that the -5V DC supply to CHARGE should actually be -5.2V DC; adjustment made! Time will tell if this voltage adjustment has any impact on the CHARGE instability which we have put down to mains problems.

3. Pete M and Pete H carried on with some spare unit testing which takes a lot longer than expected. We now have a few spare boards for the Argus, enough to hold a stock of spares in the LCP.

4. Pete M also tested (again) the RGB to VGA converter he obtained which now recognised there was an RGB input, as a result of the -5.2 V DC, but trying to drive a VGA monitor resulted in an 'out of range' message. Pete has given this a good try but the non-standard timing of the frame, etc. is defeating us.
This was our last team working Saturday before Christmas.

Dec 05
1. We removed the floor covering in the T86 radar as we knew it was really spongy when you walk on it. The T86 doors had been left open for considerable periods when the T86 was 'in store in the open' (another expression for abandoned) and evidence had already been found that water ingress had rotted sections of the floor. The floor covering consisted of the original plywood covered with a green lino and that in turn had been covered with rigid insulating sheets, that being covered with hardboard and a mottled green lino ( Swedish update). It was obviously a good water proof membrane in that whatever water got in wouldn't get out! Removing the floor covering revealed a sodden, slimy, mass of wet and rotted hardboard and plywood. Fortunately the actual floor of the T86 is aluminium but the wheel arches are steel, a bit corroded but in reasonable condition. The T86 floor is now drying out. Two issues remain; what do we do about the flooring under the Tx rack and draw/AC units?

2. Also manage to test some A700 boards, an MP140, 8 Channel Serial I/O and two ME172 Floating Point boards. All three were serviceable.

3. Back in the workshop checking out the spare Archive 2150L tape drive revealed that the rubber drive bush was turning in to a black goo. We haven't found a source of spare bushes, not surprisingly, so are sourcing a length of rubber/silicone tubing to see if the same trick as used on the original Cipher Quarterback tape drive can be used As expected the rubber bush size for the Cipher is different to the Archives!
4. Another workshop task has been to check out the two FT81 terminals and four keyboards we now have as spares. The four keyboards are serviceable although one had lost it's 'beep' but a slight tap on the diaphragm of the beeper and it was brought back to life. One keyboard is brand new and ex Bloodhound, Ser. No. BG8002. A second keyboard is also ex Bloodhound but the label with the Ser. No. has been removed at some time. One monitor originally had no horizontal hold until it warmed up but a tweak on the H Hold pot sorted that. The other had a bigger problem in that keyboards would not work, or do strange things when plugged in. This was found to be a defective SKT1, a 15 pin D-Sub. It looked like something nasty had got in to it at some stage, probably from a dead battery on the video card as this had happened to our original FT81. A good quality 15 pin, through hole, D-Sub was sourced and the faulty one replaced. The opportunity to change the hefty 3.7V back-up battery on the video card was also taken as we had recently acquired a few spares. Both monitors and all keyboards now fully serviceable.

5. The spare display monitor was taken from the workshop as last week the Tech Sup's monitor had lost its vertical hold and Pete M did his best to adjust the monitor but no way would the monitor stop scrolling . Surprise, surprise, when we fired up the LCP yesterday the Tech Sup's monitor was perfectly OK and ran all day without a problem! 

Nov 28 
1. Pete Murray checked to see if the RGB video signal produced by CHARGE could be connected to a 15" CRT monitor using an RGB to VGA converter. The result, still no joy but sort of expected. Pete took some pictures off the scope such as RGB timing and further investigations will take place off-line. We need to understand the RGB requirements of the Mitsubishi monitor and work back from that, is the RGB it expects actually 'standard' RGB?

2. Neil and Ian spent the day in the T86 removing covers then removing their chrome handles. Neil confirming that we now have a complete set of keys for all the locks in the T86 which, including the door lock, comes to six! It took two visits to a local locksmith to sort the lack of keys of which none were in the radar when it was acquired. As in the previous week a bit more board testing, specifically GX and GL processors which were not serviceable. Perhaps off-line learning to fault find and repair these units is a top priority - along with all the other top priorities.

3 The Tech. Sup's monitor lost its vertical hold and no amount of adjusting could stop the picture 'wandering' in the horizontal. Remember, the display monitors are mounted in the console on their ends so Vertical as displayed is actually Horizontal re adjustment. We'll have a look at this monitor again next week and if necessary remove it to the workshop for fault finding.

Nov 21
1. Initial tests on RGB to VGA conversion for the display monitors using an Extron Video Converter which will convert RGB to VGA. The plan was to carry out some initial testing with CHARGE connected to a 15" CRT monitor. CHARGE uses non-standard video frequencies, so there are no guarantees that the converter/monitor combination would work and today we did not have success so will continue testing next week.
2. Set about removing covers in the T86 radar racks so they can be sent for re chroming. Sounds easy enough but one little problem was that we do not have the EHT key or keys to fit the covers on the Tx rack! The locks I had keys made for last week fit the drawers in the cabin but NOT the Tx covers. Also, what I thought was an EHT key wasn't. We did manage to remove most covers and the actual EHT interlock lock. So it's back to the locksmith tomorrow!

3. Most of the day in the LCP was spent testing our spare A700 cards. We ran the sim, checked everything was OK and then systematically replaced the known good cards in the A700 with 

4 Checking all our A700 cards in live simulator. Over the past year, at least, we had replaced cards to resolve faults etc. but it was the usual problem of did we think a card was U/S but it was something else causing the fault etc. etc. Anyway, some surprises, one being an ME170 GX processor that was thought to be U/S wasn't and also discovered that the ME172 Floating Point Processor in situ was in fact U/S as it gave corrupt bearing information on the P Display between 340 - 350 degrees - something that was noticed by chance! Bottom line: We have a serviceable set of cards in the LCP's A700 and at least one serviceable spare for each card. The U/S cards we will need to get repaired. A700 board swapping is something we wouldn't have done up to a few months ago as it was certain to cause more problems than it fixed but as the simulator now runs reliably, we power it up and down, swap boards and it still runs just fine unlike the many months spent when it developed a fault or stopedp running when we took a tea break (hope I haven't spoken too soon)

Nov 14
Had a productive day refitting all the lamp lenses on P-Rack. The simulator ran well again following an initial problem with a WEETABIX card at power on, not a fault as such as the WEETABIX cards just needed pulling and re inserting. The simulator ran well apart from a couple of display (mains) glitches which always happen at lunch time. The reliability of the simulator is now so good we refitted the covers to the computer racks!TRying to develop a stoppederiBus simulator. Yet to be completed but the timing of the serial PeriBus L5 and L6 is done as is one of the L1/L4 lines. This will enable us to drive the I/O cards for stand-alone testing.

Nov 07
The many domed plastic lamp lenses on P Rack were removed for cleaning and repair where the small metal band around the base breaks so the metal insert comes away when trying to unscrew the lens - soon resloved with 'super glue'. 

Oct 24
Refitting the chromed handles nearly completed on LCP racks. CTryingresolvedARGE errors still halting the processor occasionally; mains power glitches are the primary
suspect now. 

Oct 17
1. Refitting rechromed drawer handles and latches.
2. Ian fitted wooden storage racks that he made for the top of the racks.

Sep 19
1. A tracker ball problem that has been around for a while was at last resolved today. It was a fault that we have lived but now needed fixing especially as it caused a problem last Saturday when demonstrating a jamming target. The tracker ball fault manifested itself when the simulator was switched on, it worked in azimuth for a while then stopped working completely. It was found that the +5V on the 8 port interface panel, rear of the I/O rack, was only +3.8V at the tracker ball encoder interface. Neil persisted with the fault finding and found that 1.2V was being dropped in the 8 port interface by a wire connecting the interface isolating switch on the panel to the tag strip that feeds +5V to the connectors for the console keyboards and tracker ball. The wire was bypassed to prove the fault. The result, the tracker ball worked perfectly. On occasions the Tech Sup keyboard also failed to work, that too is now also fixed. The suspected problem with the 8 port interface panel was oxidized crimp on the wire. We tested our spare 8 port interface unit which also proved to be U/S with no tracker ball control whatsoever. Taking both units home to repair.

2. Established that the CHARGE and display problems are 100% due to poor mains; doubly confirmed by running on a generator.

3. So today we can say that we switch on, the simulator boots, and runs perfectly – every time we power on.
                                                              Three years and two months after we pulled the LCP out of the long grass and nettles we can say we are there!

BMPG Diary