| Electronics > Repair |
| Vintage chip Programmer : " Micropross ROM 3000U " |
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| m k:
--- Quote from: Vince on January 03, 2023, 11:46:43 pm ---So the label on th disk is 100% wrong then. It's not just the revision number they got wrong (it says v5.5ARP) but they alos got the model number wrong ! --- End quote --- It's not stone carved. Back in the day things were a bit different, even that everything were pretty small, compared to what we have now. It's quite possible that one part is not altered and keeps its old numbers when other part is giving new numbers to all. So a marketing issue and clearly invisible is actually nothing at all. --- Quote ---From what I read on the French forum, it's not quite clear if that drive can even work on a PC. It may or may not. It may only work on Amiga systems. --- End quote --- Amiga is very different, one easier possibility is ready/change difference. It's also possible that your read errors are deliberate, for that you need a sector image with some of addendum data. One used copy protection method was putting up wrong track or sector numbers. One other was swapping CRC data. On the other hand, four errors, one after the other is not a good sign. Flip the diskette door open and check the disk visually, can you see anything alarming. For what Amiga is very good is exactly these situations. Since it was a gaming machine first, it has a hard wired copy protection something. It's case is that it can read something it can't write, the name of the thing is long track(not GCR) and it reads from index to index no matter what and software does the rest. Against writing the same there is a hard wired timer that is flipping much earlier. First level of testing is pretty easy. Just swap drives and check how disks are spinning. Drive ready, disk change and motor on are what you can test without any actual readings. Scoping pins 2 and 34 will show something also. One other thing. In case you think your data is missing something, try XOR 0xFF everything. Text is obscured that way yes, but not enough, you'll learn to see its presence. |
| Vince:
--- Quote from: m k on January 04, 2023, 07:44:02 am ---Amiga is very different, one easier possibility is ready/change difference. It's also possible that your read errors are deliberate [..] One used copy protection method was putting up wrong track or sector numbers. One other was swapping CRC data. --- End quote --- Oh no, that would be very nasty !! --- Quote from: m k on January 04, 2023, 07:44:02 am ---On the other hand, four errors, one after the other is not a good sign. Flip the diskette door open and check the disk visually, can you see anything alarming. --- End quote --- OK tried that. Removed a few specs of dust from the surface....and tried reading the disk again : 1) All 6 tracks that read bad before, read just fine now ! ... but now I have a new read error, on track 76/1... ... i.e. the track right next to the 77/1 that was bad before, so there must be something wrong in that area of the floppy. 2) So removed one more speck or two of dust..... now 76/1 is good but it's now track 60/1 that's bad. No read error per se, instead if complains that " Could not determine interleave ". Whatever that means... it can't be good anyway, I guess... 3) Seeing as the errors were random, the errors clearly could not be there intentionally, it was just a falky disk, but it seemed to improve the more I read it so... I though maybe if I read 100 times I might get lucky and eventually get a 100% error free read, at least once... I didn't have to wait 100 times though : the very next read attempt was the one ! 100% error free, look at that !!! :-DMM Needles to say I now treasure this disk image... it will let me make good disks. The original disk looked indeed really bad.. sure the dusty did not help, but the disk surface itself looks very tired : lot of circular marks, as is the drive heads actually were dragging on the surface while operating... There are also a few "dots" tat look like tiny specks of dust, but aren't : they look like tiny dents in disc, as if the heads impacted/crashed into the disk while it was not rotating. I don't know if that's even technically possible, I am no drive expert... but it does look like that. So next, I wrote that good image, to a 1.0MB DD disk... using the HD drive in the PC. Disks are NOS so unlikely to have much "data" floating around that would confuse the programmer's DD drive. Worth a shot anyway. So I made that disk, then read it back with IMD... no errors. Then wanted to compare the two images to make sure they are identical, but IMD does not seem to offer this feature, crap :( So I just went ahead and sticked the disk into the programmer to see if it could boot from it or what ! Well... works just fine, it boots on it happily and I can still talk to the programmer using a terminal, still works perfectly ! So that's cool, sanity checked passed with flying colours, we can create and write images now ! :-+ That's all for now... 00H45 here, going to bed quick. But tomorrow is friday already, so we will have more time to play with this thing ! >:D --- Quote from: m k on January 04, 2023, 07:44:02 am ---First level of testing is pretty easy. Just swap drives and check how disks are spinning. Drive ready, disk change and motor on are what you can test without any actual readings. Scoping pins 2 and 34 will show something also. --- End quote --- Hmmm, looks to me like you know the H/W part o these old drives quite well... hopefully with your help we can get something working over the week-end... Oh forgot... one last thing. I found it strange that a DD disk is 1.0MB but all the disk images I was given for the programmer were only 600+ KB i size. Such a waste a precious storage space just didn't make any sense. So I thought hey.. maybe it's formatting problem... 1.0MB might be valid only for PC formatted disks, but since the programmer uses a different format... the total available size might be different as well. So I made the calculation : Two sides, 80 tracks per side, 16 sectors per track, 256 bytes per sector.... 2 x 80 x 16 x 256 is about 650KB ! NOW it does compute !!! :-DMM See you later..... :=\ |
| pcprogrammer:
The 1.0MB is unformatted space. The formatting takes away parts to store data for things like error checking. http://209.68.14.80/ref/fdd/formatCapacity-c.html |
| m k:
--- Quote from: Vince on January 05, 2023, 11:46:38 pm ---Hmmm, looks to me like you know the H/W part o these old drives quite well... hopefully with your help we can get something working over the week-end... --- End quote --- Around the board many have been banging their heads with these things through the years, so I'm sure somebody will be around and you'll be fine. For your floppy stuff, back in the day many things happened, open environment is open for happenings. The actual floppy era was even worse, like paper clipping a note to a one and then putting it under a pile of chronological mail. But for 360k floppy that was most likely just a business as usual. It's also possible that the reason for your read errors is finally the head and its dirt, those markings on the disk have donated some material. For that I had a flat plastic made J-hook, it reached behind the spinner part and with a sort of a cotton sock and some freon it did the job. Cleaner disk is for personal use only, any more than that and it becomes unpractical, J-hook is also much faster. For your possible drive things, since you have made a working copy your real problems are none. If your original drive stops working you can always change it to a PC drive. Some nuances may remain but you can read and write disks with your programmer. The earlier link with yellow background picture. There the bottom HP format, that's probably close to what your programmer is using. Few copy protections, one of the nastier one I can remember was where the disk was physically damaged by punching a hole to the data area. Obviously edges of the hole were not level so it had a possibility to damage the drive. It didn't help that the disk had to be accessed during every start and data was written over the hole. One other was for the hard disk, there data was written where normally was nothing. Means that you can't swap or format the drive because that extra data disappears and then the disk is not accepted anymore. Luckily it was just a plain text and a hacker nature of an eager repair man revealed that. |
| Vince:
OK, I pulled the floppy drive of both the programmer and the computer. Pics below. First the HD drive in the vintage computer : it's the usual flimsy / cheap style, made by ALPS. First strange/suspicious/ worrying thing I notice, is the total absence of any jumper at the back. Also, the sticker says it's an IBM part number.... so it ads up. Bloody IBM set the configuration of the drive in stone, to suit its Aptiva machine. Second, the programmer's DD drive. It's the opposite of the HD drive : weighs at least twice as much, beautiful die cast alloy chassis like the old 5.25" used to have,, cool stepper motor to spin the disc, and a big ass motor to move the head, in contrast with the minuscule ridicule tiny motor at the back of all these flimsy more modern drives. Also has plenty of jumpers, on the side not at the back, see pic. 6 of them, which read : S0 S1 S2 S3 SH AH I understand floppy controllers can address up to 4 drives so drives have jumpers to be set as one out of these 4, so I guess S0 to S3 is meant to tell the controller which drive number it is. Currently set to S0 which makes sense I guess. However good luck figuring out what SH and AH mean. Drive is from BASF, so German... but "Made in Japan" none the less. So first I tried plugging the HD drive into the programmer. Since that drive has zero jumpers, I didn't have much to think about. Programmer didn't like it at all : upon power it up, it beeps / complaigns, and does nothing at all with the drive, it just won't touch it.... no noise, no LED, nothing. Then more interesting, I plugged the DD drive into the old computer. No go either here : BIOS complains about it at boot and forces me to modify settings. BIOS offers me only 3 choices, none of which match the drive. I have to choose from : 3.5" 1.44MB 5.25" 360ko 5.25" 1.2MB At boot the BIOS recognizes it, or default to I should say maybe, 5.25" 1.2MB, as drive B not A ! Whatever. I I booted with that setting. MS-DOS does boot, but when I try to select drive A:, it fails miserably so I have to go back to the hard drive instead. So it's not looking good at all, the DD drive is too custom and old to work with the custom BIOS of the custom motherboard of this 100% custom old IBM computer. Too much work figuring out the DD drive and IBM BIOS... too costly to buy a different vintage computer with a standard BIOS that could accommodate any floppy drive type...just so I can try to maybe, with no guarantee whatsoever, manage to make use of the oddball DD drive of the programmer. No... in the short term, the quickest and cheapest way out is to keep doing what I have just done yesterday : write the SD floppies with the HD drive, knowing my box of DD floppies is NOS so blank, no old data on them to mess things up when reading t back after having written an image on it. Worked just fine with the first boot disk yesterday, so although it's not reliable 100%, it appears to work well enough to let me go further with this programmer.... so that's what we will do. It's frustrating because as far as I understand it, that guy on the French forum who restored hi 5000 model, DID put the programmer's DD drive in his computer to write the image, and it worked just fine.... HOWEVER the drive in his programmer is NOT at like mine ! Look below, he took a pic of it : it looks very different to mine, and very very similar to your cheap HD drive, similar construction, and setting jumpers at the back, with different marking than mine, notably an " MM " jumper, a " READY " one and a " TTL / CMOS " one. Made in Japan by " CHINON ", model FZ-354. He did say that eventually this drive was faulty (would give errors towards the end of the disk) so he replaced it with bog standard DD drive which modified a little bit IIRC. So I guess his programmer was a bit more recent than mine. Anyway, so now the next step is to write a DD boot disk (with the HD drive then) for the ROM3000B image that I was given, which matches what the MS-DOS remote control S/W expects and is meant to work with exclusively. But before that, I must figure out how to convert the image file into the IMD file format so IMD can make use of it. I saw a few convert utilities that came with IMD. There is one called " BIN2IMD " for example. Trouble is, I don't know what is the file format of the image files I was given... I don't know what formats exist out there. Is there any to find out ? Maybe read the image file with a HEX editor to see if there are some metadata at the beginning of the file with some ASCII text telling us what format is being used ?! I don't know... :palm: |
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