On Wed, 19 Nov 2003 at 23:12:47, Romaldo Parodi wrote:
(ref: <[EMAIL PROTECTED]>)
>
>
>>>>Has anyone come across a spem internal memory expansion?
>>>>
>>>>How was this implemented in the QL?
>>>>Was it one that simply plugged into the 8301 socket - with through
>>>>connector and wired to the 68008?
>>>
>>>I had one some years ago. This one is plugged into the 8301 socket, bat
>>>the added memory is handled by 8301 like original memory.
>>>Pins 2,3 and 10 of the ZX8301 are plugged outside the original socket
>>>disconnecting in fact A17, A16 and CAS1L; new signals A17,A16 and CAS1L
>>>are generated by PAL16L8 using also A19 and A18 by the 68008. PAL16L8
>>>generates also a new address line for 41256 memories, CAS0L and CAS1L
>>>for two blocks of 256 Kbytes memory
>>.. so there is no connection outside the 8301 then.
>
>Only address lines A18 and A19 from 68008. Main boards issue 6 or 7 may
>require to connect a third wire if you get only 192 Kb of memory
>instead of 640 Kb. Unfortunately I do not remember further details
>about this link (-:
It appears not for the spem. He has only connections to the 8301
socket.
--
QBBS (QL fido BBS 2:252/67) +44(0)1442-828255
tony@<surname>.co.uk http://www.firshman.co.uk
Voice: +44(0)1442-828254 Fax: +44(0)1442-828255
TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG
