Apple-2-HW/ssc
2
0
Fork 1
mirror of https://github.com/jmthompson/ssc.git synced 2025-01-02 14:31:17 +00:00
Code Issues Projects Releases Wiki Activity

Sync to tested version.

Browse Source
This commit is contained in:
Christopher RYU 2023-03-10 06:38:33 +09:00
parent 65affd5d25
commit 286b063f41
1 changed files with 6 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
gal/ssc_gal_wincupl.pld
View File

@ -32,7 +32,7 @@ Pin 18 = eprom_a9;
Pin 19 = eprom_a10;
Pin 20 = rom_enable;
Pin 21 = PHI2;
Pin 22 = d0;
/* Latch (RS flip-flop) definition:
Q = (Q & RESET) # !SET;
@ -40,14 +40,17 @@ Pin 22 = d0;
PHI2 = !slot_select; /* per schematic */
cf00_access = io_C800 # !A8 # !A9 # !A10; /* CF00 access, pull low */
cf00_access = io_C800 # !(A8 & A9 & A10); /* CF00 access, pull low */
/*
if either reset or cf00 access is pulled low, then rom_latch = 1
if io_slot_access is 0, then rom_latch = 0
if io_slot_access is 1, then rom_latch = no change
*/
/* Q = ROM_LATCH RESET = io_slot_access SET = (reset & cf00_access) */
rom_latch = (rom_latch & io_slot_access) # !(reset & cf00_access);
rom_c800_enable = rom_latch # io_C800; /* enable if both pulled low */
ls245_enable = ( io_slot_access & rom_c800_enable & slot_select); /* c800 ? */