CorComp used TI code (intellectual property)?

[ckoba]

I've just dumped the ROM of a CorComp RS232 PEB card, and it's nearly identical to the TI RS232 card. The differences, based on Thierry's disassembly, appear to be confined to the initialization of the parallel port, except for a snippet at the end that I can't parse.

 

This thing is 99% identical to the TI ROM. Didn't TI aggressively protect its' IP back then?

[23:07:41] slab:~/ti/rs232$ diff -u 0 1

--- 0    2016-04-03 23:07:41.193333672 +0900

+++ 1    2016-04-03 23:07:30.075064783 +0900

@@ -100,7 +100,7 @@

 00000630  56 60 40 72 c9 01 ff fe  10 23 c9 0b ff 88 06 a0  |V`@r.....#......|

 00000640  48 70 13 03 06 a0 48 80  10 fa c0 c3 16 0e 04 c6  |Hp....H.........|

 00000650  36 06 1e 12 1f 0b 13 07  1f 0c 13 05 d2 e4 ff 7b  |6..............{|

-00000660  13 0f 1f 0a 16 0d 04 60  44 5c 1d 01 1e 02 1f 02  |.......`D\......|

+00000660  13 0f 1f 0a 16 0d 04 60  44 5c 1d 01 1e 02 1f 16  |.......`D\......|

 00000670  16 03 06 a0 48 80 10 fb  04 c6 d1 a0 50 00 1d 02  |....H.......P...|

 00000680  c2 e4 ff 88 04 5b c9 0b  ff 88 d1 c7 13 09 06 a0  |.....[..........|

 00000690  46 b4 02 27 ff 00 c9 07  ff 7e 02 07 01 00 10 06  |F..'.....~......|

@@ -126,18 +126,23 @@

 000007d0  ff 00 09 41 2a 41 0b 71  2a 41 06 c9 04 5b d1 af  |...A*A.q*A...[..|

 000007e0  fb fe 10 01 c1 bb c9 0b  ff 8c c0 c3 16 0d 1d 10  |................|

 000007f0  1f 1b 16 02 1f 16 13 03  06 a0 48 80 10 f6 32 06  |..........H...2.|

-00000800  1e 10 c2 e4 ff 8c 04 5b  1e 01 1f 02 13 f5 d8 06  |.......[........|

-00000810  50 00 1e 02 1f 02 13 03  06 a0 48 80 10 fb 1d 02  |P.........H.....|

+00000800  1e 10 c2 e4 ff 8c 04 5b  1e 01 1f 16 13 f5 04 60  |.......[.......`|

+00000810  49 00 1e 02 1f 16 13 03  06 a0 48 80 10 fb 1d 02  |I.........H.....|

 00000820  10 f0 c0 c3 13 03 1d 02  1e 01 04 5b 1d 1f 32 24  |...........[..2$|

 00000830  ff fa 1e 0d 33 24 ff fe  d0 64 ff 7d 13 01 1d 12  |....3$...d.}....|

 00000840  04 5b c0 64 ff 76 60 64  ff 74 02 21 ff f6 a0 7b  |.[.d.v`d.t.!...{|

 00000850  d7 e4 00 03 10 00 d7 c1  04 5b 02 01 20 20 b0 64  |.........[..  .d|

 00000860  ff 72 02 02 00 0e db c1  ff fe 06 02 16 fc 04 5b  |.r.............[|

-00000870  c0 c3 16 04 1f 1b 16 01  1f 15 04 5b 1f 02 04 5b  |...........[...[|

+00000870  c0 c3 16 04 1f 1b 16 01  1f 15 04 5b 1f 16 04 5b  |...........[...[|

 00000880  c0 4c 02 0c 00 24 30 e0  40 73 1f f5 13 04 30 e0  |.L...$0.@s....0.|

 00000890  40 74 1f f5 16 02 c3 01  04 5b c3 01 04 60 44 5c  |@t.......[...`D\|

 000008a0  ab cd 0b 80 0b 80 0b 80  0b 80 0b 80 0b 80 04 5b  |...............[|

 000008b0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|

 *

-00000ff0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff b3 e0  |................|

+00000900  02 2c 00 1e 30 46 06 4c  0b 16 30 46 06 4c 0b 16  |.,..0F.L..0F.L..|

+00000910  30 46 06 4c 0b 16 30 46  06 4c 0b 16 30 46 06 4c  |0F.L..0F.L..0F.L|

+00000920  0b 16 30 46 06 4c 0b 16  30 46 06 4c 0b 16 30 46  |..0F.L..0F.L..0F|

+00000930  0b 86 02 4c ff 00 04 60  48 12 ff ff ff ff ff ff  |...L...`H.......|

+00000940  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|

+*

 00001000

[Opry99er]

Interesting.

 

Although I imagine if 10 of us wrote our own routine to clear the screen or fill the bottom half of the screen with 'X's, there would be very little difference in code.

 

I am less familiar with hardware ROMs and DSRs, but I can see how they would be very similar, since both pieces of hardware do exactly the same thing.

 

And maybe they pirated it. Who knows. It is interesting, either way.

Edited April 3, 2016 by Opry99er

[ckoba]

It is very curious. And it's more than writing a routine to clear a screen; this is bug-for-bug identical with the TI DSR, right down to the runaway interrupt issue.

 

Like I said, only differences are the single-byte value the PIO port is being initialized with and that patch at the very end. 4096 bytes of machine and about 1% variance, all in data? That the DSRs were developed independently stretches belief beyond the breaking point. And I'd have thought that TI would have stomped all over this ... very curious.

 

But, hey, same DSR means that it's compatible with the TI board

[Tursi]

It's not fluke, not that much code, and not in assembly. But I never knew if they were allowed to -- there are others here better versed on the history side.

[ckoba]

It's not fluke, not that much code, and not in assembly. But I never knew if they were allowed to -- there are others here better versed on the history side.

 

I'm curious enough to hear more, even off-the-record.

 

I've been dumping ROMs of every bit of gear that passes through my hands; I suppose I should make them available to others. They're at https://www.disavowed.jp/ti/roms/