Subject: ICxx71 ram adaptor for use with eprom programmer
From: [email-masked] (robert.f.casey)
Date: 3 Nov 91 21:13:40 GMT
Newsgroups: rec.radio.amateur.misc

copied from packet:
 Msg# TSF  Size #Rd  Date  Time From   MsgID        To
63934 BN   2638   0 24-Oct 0027 DG8FZ  91A211DG8FZ  ICOM@WW (NONE)
 Sb: IC-xx71-ram-adapter (1. update)

de DG8FZ @ DB0SIF

how to read/programm the ICOM-battery-RAM by EPROMER:

      Adapter ICOM-RAM <==> 2764-Programmer socket
12.dez.89      ....................
               .       R    5V  20.------ 28  +5V the factory programs
Q4-7 16-19 -+  .       A  CS    19.---(*)         the lower 255 Nibbels...
 0V  14 ----+-- 1 E    M  AD 9  18.------ 24  A 9
               .2         AD 8  17.------ 25  A 8 you find the frequency-
+5V  28 --o..o- 3 WP   U  AD 7  16.------  3  A 7 range reading the 'hexdump'
 Q3  15 -------.4 D3   N  AD 6  15.------  4  A 6 backwards.
 Q2  13 -------.5 D2   I  AD 5  14.------  5  A 5
 Q1  12 -------.6 D1   T  AD 4  13.------  6  A 4 my tnx to dl8scu @ db0aaa,
 Q0  11 -------.7 D0      AD 3  12.------  7  A 3           df8wu  @ db0lj ,
Prog 27 -------.8 WR'     AD 2  11.------  8  A 2           dc4fe          &
testet with:   .          AD 1  10.------  9  A 1           dl8zaw @ db0sif
IC-751 , 271h, . upside   AD 0   9.------ 10  A 0
   471e,1271a. ....................

 CE--20-inv.--
 OE--22-      nand--(*)    use a 4011 for the nand's and the inverter.
        nand--             dont forget to set the unused 4011 inputs high.
 PGM-27-

if your eprommer cancels operation with a 'no eprom inside'-error
contact each eprommer-pin to a normal 2764 but
dont connect the pins  11,12,13,15,27 of the normal eprom,
dont connect the pins  16-19 to 0V as shown above,
program the 2764 to all bytes = low before.

73's de Karl  (dg8fz @ db0sao.deu.eu) 12.Dez.89, 21.Okt.91
===========================================================================
Note: I haven't tried or verified this, proceed at your own risk.  Please
direct questions to [email-masked] on packet.   WA2ISE