| Electronics > Repair |
| Vintage chip Programmer : " Micropross ROM 3000U " |
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| pcprogrammer:
Hi Vince, interesting results, but I think your interpretation is off. My view on it is that the PC sends BOOT and then the programmer replies with BOOT 00. Then the PC sends HELO to inquire for the model information and the programmer responds with HELO 00 30 00 5.00 5.40 AP. What you can try is to just use a terminal program like hyperterm and send the BOOT command to see what happens. The baud rate might be low as 1200. You can use a scope on the signal to try to measure it. Based on the bit pattern of the letters it should not be that hard to do so. Cheers, Peter |
| Vince:
--- Quote from: pcprogrammer on December 30, 2022, 05:57:38 am ---interesting results, but I think your interpretation is off. My view on it is that the PC sends BOOT and then the programmer replies with BOOT 00. Then the PC sends HELO to inquire for the model information and the programmer responds with HELO 00 30 00 5.00 5.40 AP. --- End quote --- After a good night of sleep... I think you are perfectly right, makes more sense ! :-DD Plus it's common practice for a recipient to repeat the keyword of the sender, as an acknowledgment, to increase reliability of the coms. Also, that " EX " character at the end of the reply from the programmer, is probably again a safety feature, means " I am done, I have sent everything I wanted, I am not going to send anymore data to you, you can send me a new command whenever you want ". --- Quote from: pcprogrammer on December 30, 2022, 05:57:38 am ---What you can try is to just use a terminal program like hyperterm and send the BOOT command to see what happens. The baud rate might be low as 1200. You can use a scope on the signal to try to measure it. Based on the bit pattern of the letters it should not be that hard to do so. --- End quote --- Yes ! I need to do that.... 1200 yes I think I read somewhere in the manual taht it's a common default value for these programmers, or a suggested value. I think it sais that it can 19,2000 bauds maximum, but that for reliable operation you really would be well advised not exceed 9,600 bauds grand maximum. I guess it all depends on the length and quality of the serial cable is being used. Problem of course, as you can see... bench is FULL ! How on earth do you expect me to access and use a scope ?! :-DD I guess I can make some space by rendering the programmer headless again... get rid of the big TV, the bread board and video board, close the lid of the programmer.... might do it. Maybe I could even get rid of the programmer altogether and just probe the end of the serial cable directly rather try to probe it while both ends of the cable are being used... The programmer won't b able to reply but the PC should still at least send the first character in " BOOT ".... I should get a 'B'.... UNLESS the PC uses H/W flow control (and the manual says it can, the pins on the programmers DB25 are all wired up.... ) hence I am screwed. But let's just try zand see what happens ! ;D STAY TUNED !!! >:D |
| Robert763:
On DD / HD disks and drives there are two issues. First is the level of magnetisim used. Second is the width of the head and the track it makes. The magnetism is more of a problem when trying to write a HD disk in a DD (or SD) drive. The HD drive can identify a DD disk (hole in corner) and adjustments made. So this does not affect his case. The head / track width can be an issue. The heads in SD/DD disks are wider than those in a HD. If a DD disk is written in a DD drive (wide tracks) and then written to in a HD drive not all of the existing track is over written. This does not affect the HD drive because it only reads the track it wrote. If it is then read in a DD drive you can get bad data because the had covers both the remains of the old track and the new narrow one. To stop this problem if using a HD drive to write a DD disk it is best to use a brand new disk, a freshly erased one or one that has only been written in a HD drive. After writing on it in the DD drive don't write to it again in a HD. All this depends on a lot of variables so it is not 100% certain what will happen, but it is my experience from using lots of disks in lots of different drives and machines over the years. I still have some used DD 3.5" disks that came from a buliding society (bank) and had been bulk erased. They are the best for use in odd systems. Robert. |
| Vince:
Thanks Rob, interesting details ! :-+ So to minimize headaches, it's best as was already suggested before I think... that I just pull the drive out of the programmer, and shove it into my vintage PC. I think that's what that guy on the French forum might have done... need to scroll back and re-read the thread more carefully and start taking notes.... For the fun of it I will try to see if there is a way, just by looking at it, to tell if a drive is HD or DD. I could look at my stock of old drives and see if I have a DD one maybe. Just for the fun. |
| Vince:
OK made some mandatory space on the bench... removed the big TV and the programmer itself altogether... that made just enough to fit the HP MSO, perfect for the job... takes little space on the bench, light, and the Megazoom feature makes it an excellent tool for the job at hand, I love it. Too bad its logic analyzer is geared toward // system only, it can't do serial decoding it seems... that was not the hype back then I guess... It's more targeted at 8 CPU systems I guess. Can sniff an 8 bit bus + up to 8 control signals & clocks. I installed the "SeriatTest" monitoring S/W that Neomys suggested on TEA... I can't get it to work. Looked at the help files and it does say that needs to be used in conjunction with a serial cable that redirects to another COM port... I don't have these cables nor a second COM port. It really doesn't look like spying serial chatter generated by an MS-DOS application is possible without a second COM port and special splicing cable... >:( Anyway, I used SerialTest as a simple terminal, to send characters to the scope so I could set things up. I am rusty so it took me 30 seconds to remember that the RS232 voltage levels use a reversed logic... negative voltage means logic high, so I asked the scope to invert the signal... much better. Also forgot if the bits were sent LSB or MSB first... sent a few "test" characters to help me with that... looks like it's LSB first. OK so then I fired up the ROM300U MS-DOS S/W, hoping it would send its keyword "BOOT"..... but no. It does not send anything at all.... which means it probably requires the use of H/W control lines, bummer. So I have no choice but bring back the programmer onto the bench... it's gonna be very messy again :palm: Plus I don't have a breakout box to scope the traffic if both ends of the cable are being used, so I need to cobble something together, sure is not going to look pretty ::) |
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