Viasyn disk 1b boot prom

[Al Kossow]

Has anyone dumped the Disk1B boot prom?
I have a 286 board coming, but I only have a Disk1, which doesn't have all the boot options of the 1B

 

[hmb]

Were you perhaps referring to the Disk1A ? To the best of my knowledge no documentation exists for the boot ROM on the Disk1B to explain the selections it provides, though I recall figuring out from trial and error that they roughly match the same options provided by the Disk1A.

Boot ROM version 291C for the Disk1A provides four routines for Compupro's 8086 and 80286 CPUs, allowing for booting from either an 8" or 5.25" floppy drive connected to the Disk1A or a hard drive connected to the Disk3. A dump of the Disk1A 291C ROM is available in the library of Compupro ROMs and PALs posted to several software repository sites.

 

[hmb]

An additional issue...

Your Disk1 was designed for a 24 pin 2KB ROM, whereas the Disk1A (with a selection of 4 boot routines for each of CompuPro's x80, x86, 68K, and 32016 CPUs) was designed for an 8KB ROM, so they are not easily interchangeable. Since the Disk1A standard 8K ROM held exactly 16 512-byte boot routines, I suppose you could just copy the four 512-byte blocks you need for the CPU286 into a smaller ROM. The only other issue would be to verify there are no substantive differences in the I/O port specifications between the Disk1 and 1A - I don't think there are any aside from those required to support both 8" and 5.25" drives on the Disk1A.