Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!rutgers!bellcore!texbell!killer!elg
From: elg@killer.Dallas.TX.US (Eric Green)
Newsgroups: comp.sys.cbm
Subject: Re: C128,C128D, and C128C??? Questions
Message-ID: <7605@killer.Dallas.TX.US>
Date: 22 Mar 89 01:25:22 GMT
References: <1856.2423BC06@isishq.FIDONET.ORG>
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 42

in article <1856.2423BC06@isishq.FIDONET.ORG>, izot@f171.n221.z1.FIDONET.ORG (Geoffrey Welsh) says:
> (1) Why didn't the C128 include 64K video RAM from the beginning? Considering 
> that the VDC was designed to handle 2 4416s or 8 4164s (but has also proved 
> workable with 2 4464s), it seemed the logical thing to do...

4416s were around $6 apiece on the consumer market at the time. 4464s
were about $40 at the time (remember, this was when 256k DRAMs were
new). 

> (2) Given that the 128's MMU could handle FOUR 64K banks of memory, why was 
> that capability not used? 41256s were a commodity chip at the time 

See above. Plus, the continuing shortage of 41256's is yet another
disincentive. 

However, I have another pet peeve: Even if you put 256K of RAM into
your Commodore 128, the system software, and BASIC in particular, is
set up only to access 128Kb of RAM.

> achieve it. Since I am not a video specialist (that is probably the area where 
> I lack experience most), I figured at first that it was me. However, I have 
> been told by several people (including a fellow named Jeff Solomon, who claims 
> to be a "Commodore rep") that there is a bug in the VDC that prevents bitmap 
> and interlace modes from being enabled at the same time.

I have a program and several pics that use the 640x600 display. I
suspect it'd look great on a multisync monitor. Alas, all I had
available was an old CGA monitor borrowed from my brother's office.... 
Call it an existence proof, in any event, that it IS possible.

BTW, I upgraded my C128 to 64K of video RAM simply by popping the
darmned things in there. Seems to work, although perhaps in normal
operation the computer thinks it only has 16K of video RAM. However,
if so, programs which take advantage of the added RAM seem to detect
it and re-init into 64K mode, so that wasn't a problem.

> FidoNet:   Geoffrey Welsh on 1:221/171               | Kitchener, Ontario

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