Looks good, doesn't it? Shame it didn't bloody work and not just due to missing grounds, as i would discover to my horror later on...
So, while i put the board back down and began to ponder, i decided to have a crack at the GLU chip, which as the name implies, handles a few basic glue logic functions like selecting the floppy drive and buffering the clocks. It's a HAL16L8 part that should be easily replicated. However, i pulled the data out using the following schematic:
which, when read as a 27C020, netted me a .bin file, and using a PAL Analyzer, got something that mostly made sense, but with a whacked out /OE that was 9MB long. WinCUPL crapped its pants at almost every point, and seems to be so buggy it doesn't like being used on windows 10...
Code: Select all
Name HAL16L8;
PartNo ;
Date 2020-07-13;
Revision 0.1a;
Designer Kai Robinson;
Company ;
Assembly ;
Location United Kingdom;
Device g16v8a;
/* Dedicated input pins */
pin 1 = I0; /* NC*/
pin 2 = PB6; /* PB6 */
pin 3 = IRQ; /* IRQ */
pin 4 = WRDATA; /* WRDATA */
pin 5 = ENBL1; /* /ENBL1 */
pin 6 = PA4; /* PA4 */
pin 7 = CLK; /* CLK INPUT*/
pin 8 = PA3; /* PA3 */
pin 9 = RTxCB; /* /RTxCB */
pin 11 = OE; /* OE */
/* Programmable output pins */
pin 12 = RTxCA; /* Combinatorial output */
pin 13 = OutA; /* Fixed high output w/ output enable */
pin 14 = IPL0; /* Combinatorial output w/ output enable */
pin 15 = ENABLE_L; /* Combinatorial output */
pin 16 = ENABLE_U; /* Combinatorial output */
pin 17 = FLOPPY_WR; /* Combinatorial output */
pin 18 = B6; /* Fixed high output w/ output enable */
pin 19 = FCLK; /* Combinatorial output w/ output enable - FCLK on BBU Pin 44 */
/* Output equations */
!FCLK = CLK & !OE;
B6 = 'b'1;
!FLOPPY_WR = WRDATA;
!ENABLE_U = !ENBL1 & !PA4;
!ENABLE_L = !ENBL1 & PA4;
!IPL0 = !PB6 & IRQ;
OutA = 'b'1;
!RTxCA = !PA3 & !RTxCB & !OutA
# PA3 & !RTxCB & !OutA
# !PA3 & RTxCB & !OutA
# PA3 & !RTxCB & OutA;