Jump to content
IGNORED

Boxcar RS232 DSR dump needed


atrax27407
 Share

Recommended Posts

The data lines to the EPROM are jumbled. If you re-order the bits in each byte as follows then it all makes sense:

 

Original data: D0-D1-D2-D3 D4-D5-D6-D7

EPROM data: D1-D5-D7-D0 D4-D6-D2-D3

 

For example, the first byte of the DSR header is AA (1010 1010), and this is 1E (0001 1110) in the EPROM.

Link to comment
Share on other sites

Bad engineering or attempted subterfuge?

 

Well, sometimes it is easier to route the traces for a board if you can re-assign the pins on a device. The pin order on the sideport for these signals is in a pretty crazy order. That said, doing it on purpose to something like an eprom that requires a contract with another device, is evil. If their goal was subterfuge, then it was clever. If their goal was to save a batch of pcboards that were designed wrong, then it was resourceful. If their goal was to just be easier, then I'd call it lazy, but that is me being judgmental, without any knowledge of 1980s EDA tools.

 

I just did this on my TIPI project, but that was a MISTAKE. Not intentional, will be corrected before release.

 

-M@

  • Like 1
Link to comment
Share on other sites

Due to the efforts of Richard Bell, we now have a dump of the Boxcar RS232 as seen through the scrambled address lines as seen from the console. However, to burn a replacement EPROM one would still have to use the one previously posted. Here is how it appears unscrambled.

Awesome! Glad he got to the unscrambled one. I was about to do a mini memory dump :)

 

I dumped mine for comparison too, it has "V1.1" on it.

bocxar_e232_v1.zip

  • Like 2
Link to comment
Share on other sites

Wrote a quick and dirty Geneve program to scramble/unscramble the EPROM.

Acadiel's v1.1 appears to be the same as what Swim dumped.

If you update the baud rate table, I can scramble the binary so that you can burn it.

 

To unscramble the EPROM contents, the bits are re-ordered as follows:

EPROM[abcd efgh] -> [dagh ebfc]

post-25764-0-99385500-1504555707.pngpost-25764-0-50376800-1504555827.png

  • Like 4
Link to comment
Share on other sites

Insane Multitasker and I "double teamed" the Boxcar RS232 file. I took the existing "clear" file that we got with the DSR dump through the console which was unscrambled and altered the baud rates. The original went from 110 bps to 9600 bps. The table had been truncated by one value. I changed the baud rates to go from 300 bps to 19.2K bps I sent the file back to him and he re-scrambled it so the it could be burned directly into an EPROM (TMS2532).

 

Remember, this file is completely untested. Someone with a Boxcar RS232 will have to try the new baud rate table out. There are no guarantees that it wll work properly. Pleaae post your results (and system configuration) so everyone can share in the "fun"

BOXCAR_HS.bin

  • Like 4
Link to comment
Share on other sites

Remember, this file is completely untested. Someone with a Boxcar RS232 will have to try the new baud rate table out. There are no guarantees that it wll work properly. Pleaae post your results (and system configuration) so everyone can share in the "fun"

Once the changes (and scrambling) are confirmed, I'll post a disk image with the program source/executable and the DSR images.

  • Like 2
Link to comment
Share on other sites

b3257befb3f2b318e3f7171aa0a7f0d4.jpge651dcf581313b533b5973d7e68328b9.jpg

bcef62bdf3f898dbc54a6b3b858cafa2.jpg

 

In case anybody be wants to see this.

 

The AC adaptor is 9V, 200ma, positive tip.

 

Hmmm? I don't see a wire tying pin 21 and 24 of your EPROM acadiel? Is your pin 21 lifted from the socket or trimmed off? Ah, you have a revision "A" board maybe that's why.

Link to comment
Share on other sites

Perhaps the black case could indicate earlier board versions.

This didn't go well. I just learned "My Media" reduces the size of pics. This board has hand wiring and the EPROM has pins 21 and 24 strapped with the leg of pin 21 bent out so it doesn't make contact with the socket. acadiel's board is a version "A" and shows no hand wiring or strapping of the EPROM.
So far, I'm unable to successfully test atrax27407s high speed .bin. I can program the EPROM successfully but the EPROM does not function as expected when connected to the 99/4a console. Will investigate further as time allows.
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...