Date : Fri, 01 Aug 1997 19:35:12 +0100
From : Mike Tomlinson <mike@...>
Subject: Re: Solidisk 1770 Upgrade kit
In article <199708011644.SAA21128@...>, Mark Usher
>I have the above upgrade kit, and I would really like to look at the
>fitting instructions, as I have a feeling it is slightly different to the
>Acorn 1770 upgrade.
>ie I think that Pins 4 & 11 on IC 79 have to be linked. Can anyone back me
>up on this ?
No, that doesn't sound right. The Solidisk upgrade used the same links
as the Acorn one, so you should be OK with the Acorn instructions. I
seem to remember the Solidisk upgrade used little red IC headers with
wires soldered between the appropriate pins. The Acorn upgrade just
used wire links which were pushed into the socket holes.
If a link is present at S9, cut it.
ICs 79 and 80 have to be populated with 7438s (not 74LS38s)
If a 74LS393 is present at IC86, remove it and place a jumper between
pins 1 and 4.
If IC87 has a 74LS123, leave it there. If it's empty, fit a jumper
between pins 9 and 12.
Shove the 1770 module into IC78 and the ROM into a spare socket.