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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 |
rusure
Messages: 1030 Registered: March 2012
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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.
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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 |
Dombo
Messages: 210 Registered: December 2011
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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.
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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 |
rusure
Messages: 1030 Registered: March 2012
Karma: 0
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Senior Member |
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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.
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