6502 BASIC or Assembler and Intel 8271/WDC 1770 info req'd

From: Eric Dittman <dittman_at_dittman.net>
Date: Sat Oct 6 17:16:33 2001

> > So now I'm left with two questions:
> > 1) Has anyone got any source code for the WD1770? 6502 ASM, C, anything.
> The 1770 is pretty much compatible with the other Western Digital FDCs.
> The TRS-80 model 4 uses the 1793 (very similar in software), and the
> sources of LS-DOS 6.3.1 are on the web somewhere (Tim Mann's page?).
> That's Z80 assembly language.

The later (gate array) TRS-80 Model 4 systems used a 1773 FDC, which was
compatible with the 1793. The 1770 and 1773 were compatible, differing
only in the logic states of some of the lines, but it's been so long
since I've used either I can't remember which pins were different.

The 1770/1772/1773 had both the data separator and write precompensation
built-in. They are 28 pin devices (the 1793 is a 40 pin device).
Eric Dittman
Check out the DEC Enthusiasts Club at http://www.dittman.net/
Received on Sat Oct 06 2001 - 17:16:33 BST

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