HP 54111D Scope - ROM Checksum Error - Page 1
Forum section: electronics / testgear

author: stevelup
author_rank: Regular Contributor
timestamp: February 07, 2017, 10:23:45 am
content: HiI'm getting self test fail with a ROM checksum error. My unit is the older one with 16 x 32KB EPROMS.Firmware date: Thu Mar 10 08:24:02 MST 1988I've found a dump of these ROMs but fewer than half of the checksums match the ROMs in my unit - so I'm guessing they are for a different firmware version. Or half my ROMs have a problem, but that's unlikely given that it's working.As I see it, I have four options:-1) Burn my 'found' ROM dump to a new set of EPROMs and see what happens.2) Re-burn the 'saved' ROM dump from my unit onto fresh chips. May help? Who knows.3) See if by any bizarre stroke of luck, someone has a dump of the right ROMs4) Do nothingI had hoped re-seating all the chips may solve it, but it didn't.The last option is tempting because the unit seems to be working perfectly in every possible way, but clearly there must be an issue.The ROMs in this unit are a real mix and match selection - about half a dozen different varieties. You would guess that someone had raided the parts bin at some point in the past to do a firmware update or something, however, every chip has an original HP sticker on it. Quite odd.If I do burn new sets, I'm thinking of using non-windowed OTP EPROMS - they are so much cheaper and easier to get hold of.Finally, my EPROM programmer is a really old PITA thing that connects via a parallel port and only works on Windows XP. I had to drag an old junk PC out of retirement to do this investigation. Can anyone recommend a decent low-cost modern unit.Open to any insight!-edit- perhaps this should have been in the repair section. If so, apologies and more than happy for it to be moved!Thanks,Steve

author: stevelup
author_rank: Regular Contributor
timestamp: February 08, 2017, 05:24:45 pm
content: On an unrelated note... I found some interesting stuff poking around in the ROM dump. Right at the end, I found what looks like bits of a game:-WIPERTHRUSTGRAVITYVEL LIMPauseStartCANNEDSeededBODIESSOPHANTSMUTANTSSTROIDSPONPLANESWIPER X Y SIZEAnd some credits - presumably for the development of the whole device.SOFTWAREMORE SOFTWAREHARDWAREPRODUCTION/QACJabba DonRod BobBig Wig Bigol'toeNoWay MauzeyBilbo GogginsSnow WhatRohley BohleyMean Max MintCal KinsleyMr. AFiso CornishDarth TarczaNearly Normal NathanFrench Fry DunphyBugs ToeppenWecandodatBill & the gremlinsBig Al MontijoMechanical: –Tex Malarkee – Boxman Yergenson –and those replaceable FIRE FLINGERS Nearly New NorrisDoc Mallard: Project DuckMad Man Mark: Ace Lab TechI wonder what you do to trigger access to this!

author: stevelup
author_rank: Regular Contributor
timestamp: February 09, 2017, 09:29:53 am
content: I've figured it out - extended test 17 gets you into all this stuff.There are a few funky pattern generators, Life projected onto a flat, 2D or 3D surface, a gravity simulator and some other bits. I've not managed to trigger the 'credits' screen yet.For the 'demos' that have parameters, you can interact with them in real time using the rotary encoder. I'll grab some videos if anyone cares enough.All that said, I've still got my ROM checksum error. I've got a bunch of EPROMs on the way - I think I'll try programming the dump I downloaded.

author: TAMHAN
author_rank: Frequent Contributor
timestamp: February 10, 2017, 12:34:38 am
content: Hello,I'm definitely interested in the demos!Sometimes, reading an EPROM and writing it back solves problems. Did you try this?Tam

author: stevelup
author_rank: Regular Contributor
timestamp: February 10, 2017, 07:15:44 am
content: I'll try re-writing them from my saved dumps this weekend. I've also identified the problem with the ones I downloaded - I think they were at some point uploaded by FTP from a Windows to UNIX system in ASCII mode and so have had CR stripped wherever there was a 0x13 0x10 sequence. Four of the 16 files are damaged.I've tracked down the chap who was involved in those original dumps. Unfortunately, he cannot locate the files, but has offered to re-dump his again if necessary which is very generous.I'll grab some videos of the 'hidden' toys this evening.

author: TAMHAN
author_rank: Frequent Contributor
timestamp: February 10, 2017, 09:07:53 am
content: Hello,this is really, really odd. The scope works perfectly, but fails the self test. Strange.Either way, pls keep me posted!Tam

author: stevelup
author_rank: Regular Contributor
timestamp: February 10, 2017, 08:09:10 pm
content: I've managed to fix the ROM problem.I compared the downloaded set with a set of dumps I did myself, and managed to fix all the 0x0D / 0x0A problems - thankfully there were just seven in total. Once that was done, I then verified my set against the downloaded set and found one single byte different.I re-burned that one ROM and bingo - power on self-test passes successfully.I've done a video of the hidden menu - it's just uploading to youtube now, but will take hours as I have very slow upstream here. I'll post as soon as it's ready.

author: stevelup
author_rank: Regular Contributor
timestamp: February 10, 2017, 09:40:20 pm
content: Here you go:-https://youtu.be/pqI5XcC0Wvs