
(1) Remove the Battery
(2) Remove the RAM
(3) Fit AT28C256
(4) Enjoy
Dave H

Mine arrived safely last week (ordered when I said I would try them on whichever thread it was) and were all good...Col wrote:still waiting for my 5x chips for £4 from China, then can do it
I *think* Martin may have talked about similar issues in his E2PROM / EEPROM thread when talking about Acorn EPROM/ROM carts.danielj wrote:I just stuck an eeprom in my Care electronics cartridge in my master, and it corrupted it - twice. Is that to be expected?
d.
Code: Select all
Name ABR-Issue1-30-05-13 ;
PartNo 16L8 ;
Date 01-06-13 ;
Revision 01 ;
Designer D.E.J.Hitchins ;
Company Retro Hardware ;
Assembly Advanced Battery Backed RAM ;
Location IC3 ;
Device g16v8ma ;
/* *************** INPUT PINS *********************/
PIN 1 = NOE ; /* Not-Output Enable */
PIN 2 = ERNW ; /* Electron Write */
PIN 3 = QA ; /* Page latch LSB - 16A EC */
PIN 4 = A1 ; /* Address line 1 - 17B EC */
PIN 5 = A0 ; /* Address line 0 - 18B EC */
PIN 6 = T2 ; /* CPU clock phase 2 */
PIN 7 = A5 ; /* Address line 5 - 13B EC */
PIN 8 = MADET ; /* Master detect Low if Master */
PIN 9 = MRNW ; /* Master Write */
PIN 11 = NA23467 ; /* N&'ed add. lines 2,3,4,6&7 */
PIN 15 = NPFC ; /* Not-Page &FC - 14A EC */
/* *************** OUTPUT PINS *********************/
PIN 12 = !NCS ; /* Not-Chip Select */
PIN 13 = !NRNW ; /* Not-Output Enable on Read Only */
PIN 14 = !BIN ; /* Chip 'B' inhibit latch */
PIN 16 = !BEN ; /* Chip 'B' enable latch */
PIN 17 = !AIN ; /* Chip 'A' inhibit latch */
PIN 18 = !AEN ; /* Chip 'A' enable latch */
PIN 19 = !RNW ; /* Low output Read Not-Write */
/* *************** LOGIC EQUATIONS ****************/
NCS = NPFC & !NOE & NRNW & T2 & ERNW /* CS on Read */
# NPFC & !NOE & !NRNW & T2 & !QA & AEN & !MADET
# NPFC & !NOE & !NRNW & T2 & QA & BEN & !MADET
# NPFC & !NOE & !NRNW & T2 & !QA & AEN & MADET
# NPFC & !NOE & !NRNW & T2 & QA & BEN & MADET;
AEN = T2 & !NRNW & !NPFC & !A0 & !A1 & !A5 & !NA23467 /* Unlock &FCDC */
# !AIN;
AIN = T2 & !NRNW & !NPFC & A0 & !A1 & !A5 & !NA23467 /* Lock &FCDD */
# !AEN;
BEN = T2 & !NRNW & !NPFC & !A0 & A1 & !A5 & !NA23467 /* Unlock &FCDE */
# !BIN;
BIN = T2 & !NRNW & !NPFC & A0 & A1 & !A5 & !NA23467 /* Lock &DCDF */
# !BEN;
RNW = !MADET & !MRNW & T2 & !QA & T2 & AEN /* Write */
# !MADET & !MRNW & T2 & QA & T2 & BEN
# MADET & !ERNW & T2 & !QA & T2 & AEN
# MADET & !ERNW & T2 & QA & T2 & BEN;
NRNW = !MADET & MRNW /* Select Write */
# MADET & ERNW; /* Master or Electron */
That does not sound goodCMcDougall wrote:got my 5x Amtel EEPROMS today for £3.28, so gave 3 a spin on my ATI.
they all have the same date stamp on them, but are different chips (writting on bottom), and one does not have anything written on it![]()
anyways, seems not to be playing ball with mine![]()
i did not try them in the eUPURS board, as it's a bit fiddly with the 2 jumpers on top right.
Dave, just wanted to confirm what prog you are using to load into the swram, as i'am using MartinB's EEPROM utils![]()
and this works fine, again, when I put the battery back in and the Alliance 32k chip.....
Mr B must of been lucky, and I maybe got the 'bag of sh!t#' as perMartin wrote:Mine arrived safely last week, and were all good