Megalextoria
Retro computing and gaming, sci-fi books, tv and movies and other geeky stuff.

Home » Digital Archaeology » Computer Arcana » Commodore » Commodore 8-bit » What is the difference between 16k and 64k video RAM on a 128?
Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend 
Switch to threaded view of this topic Create a new topic Submit Reply
What is the difference between 16k and 64k video RAM on a 128? [message #193332] Wed, 04 June 2008 15:00 Go to next message
tom@startwebhost.com is currently offline  tom@startwebhost.com
Messages: 155
Registered: January 2005
Karma: 0
Senior Member
Title says it all. Looking for specific differences. What modes are
supported in 64k not in 16k? Other uses?

Thanks,

Tom
Re: What is the difference between 16k and 64k video RAM on a 128? [message #193337 is a reply to message #193332] Wed, 04 June 2008 19:32 Go to previous messageGo to next message
Cameron Kaiser is currently offline  Cameron Kaiser
Messages: 1622
Registered: December 2011
Karma: 0
Senior Member
Tom Watt <tom@wattservices.com> writes:

> Title says it all. Looking for specific differences. What modes are
> supported in 64k not in 16k? Other uses?

Colour high-res, mostly. Otherwise, some programs can use the extra memory
(HyperLink 2.5 will use it as page cache).

--
Cameron Kaiser * ckaiser@floodgap.com * posting with a Commodore 128
personal page: http://www.cameronkaiser.com/
** Computer Workshops: games, productivity software and more for C64/128! **
** http://www.armory.com/%7Espectre/cwi/ **
Re: What is the difference between 16k and 64k video RAM on a 128? [message #193340 is a reply to message #193337] Wed, 04 June 2008 21:28 Go to previous messageGo to next message
Golan Klinger is currently offline  Golan Klinger
Messages: 559
Registered: December 2004
Karma: 0
Senior Member
The Super Snapshot (v5.22 for sure, perhaps earlier versions) will use any
and all RAM, including the video RAM, to reduce disk swapping on copies.

--
Golan Klinger
Dark is the suede that mows like a harvest.
Re: What is the difference between 16k and 64k video RAM on a 128? [message #193341 is a reply to message #193340] Wed, 04 June 2008 21:49 Go to previous messageGo to next message
Anton Treuenfels is currently offline  Anton Treuenfels
Messages: 105
Registered: December 2011
Karma: 0
Senior Member
Wizardry II, III and V will use whatever size VDC RAM there is for block
caching.

"Golan Klinger" <no@sp.am> wrote in message
news:slrng4ega2.3i.no@trout.local...
> The Super Snapshot (v5.22 for sure, perhaps earlier versions) will use any
> and all RAM, including the video RAM, to reduce disk swapping on copies.
>
> --
> Golan Klinger
> Dark is the suede that mows like a harvest.
>
Re: What is the difference between 16k and 64k video RAM on a 128? [message #193345 is a reply to message #193332] Wed, 04 June 2008 23:25 Go to previous messageGo to next message
rusure is currently offline  rusure
Messages: 1030
Registered: March 2012
Karma: 0
Senior Member
On Jun 4, 1:00 pm, Tom Watt <t...@wattservices.com> wrote:
> Title says it all. Looking for specific differences.  What modes are
> supported in 64k not in 16k?  Other uses?

64K ram doesn't help when you are using ordinary 25 line by 80
column RGB text. A video expansion may be useful when you are
using a 50 line by 80 column RGB interlaced text display. Full
screen RGB bit mapped graphics may also use a video expansion.
Re: What is the difference between 16k and 64k video RAM on a 128? [message #193348 is a reply to message #193332] Thu, 05 June 2008 08:12 Go to previous messageGo to next message
Tom Lake is currently offline  Tom Lake
Messages: 450
Registered: May 2012
Karma: 0
Senior Member
"Tom Watt" <tom@wattservices.com> wrote in message
news:5ff56ce7-9aea-4aaf-89f8-9917180261e6@d77g2000hsb.googlegroups.com...
> Title says it all. Looking for specific differences. What modes are
> supported in 64k not in 16k? Other uses?
>

The manual for Basic-8 gives the details for each mode. Here's a link.

http://project64.c64.org/misc/basic8.txt

Tom Lake
Re: What is the difference between 16k and 64k video RAM on a 128? [message #193353 is a reply to message #193345] Thu, 05 June 2008 13:32 Go to previous messageGo to next message
Dombo is currently offline  Dombo
Messages: 210
Registered: December 2011
Karma: 0
Senior Member
rusure schreef:
> On Jun 4, 1:00 pm, Tom Watt <t...@wattservices.com> wrote:
>> Title says it all. Looking for specific differences. What modes are
>> supported in 64k not in 16k? Other uses?
>
> 64K ram doesn't help when you are using ordinary 25 line by 80
> column RGB text. A video expansion may be useful when you are
> using a 50 line by 80 column RGB interlaced text display.

I don't think you need 64k VDC memory for that, 16k is sufficient to
store two of those 80x50 color screens.
Re: What is the difference between 16k and 64k video RAM on a 128? [message #193354 is a reply to message #193353] Thu, 05 June 2008 14:44 Go to previous message
rusure is currently offline  rusure
Messages: 1030
Registered: March 2012
Karma: 0
Senior Member
On Jun 5, 11:32 am, Dombo <do...@disposable.invalid> wrote:
> rusure schreef:
>
>> On Jun 4, 1:00 pm, Tom Watt <t...@wattservices.com> wrote:
>>> Title says it all. Looking for specific differences.  What modes are
>>> supported in 64k not in 16k?  Other uses?
>
>> 64K ram doesn't help when you are using ordinary 25 line by 80
>> column RGB text.  A video expansion may be useful when you are
>> using a 50 line by 80 column RGB interlaced text display.
>
> I don't think you need 64k VDC memory for that, 16k is sufficient to
> store two of those 80x50 color screens.

You are clearly more knowledgable than me on this subtopic. However I
have filled a 64K video memory with interlaced text and vewed the text
one screen at a time. The 64K expanded memory contains considerably
more than 2 pages. Thats how I test whether the 128 contains 16K or
64K of video memory. I have seen programs on COMP.SYS.CBM that claim
to determine the memory size by storing and retrieving one value for a
single video memory location. My technique I beleieve is more
thorough.
  Switch to threaded view of this topic Create a new topic Submit Reply
Previous Topic: A.C.E.S. newsletters?
Next Topic: Good composite to VGA converter?
Goto Forum:
  

-=] Back to Top [=-
[ Syndicate this forum (XML) ] [ RSS ] [ PDF ]

Current Time: Thu Mar 28 12:48:37 EDT 2024

Total time taken to generate the page: 0.56646 seconds