[Coco] Implications of the Speed Up Poke

[Bill Pierce]

I'm pretty sure that should read "doesn't refresh [video] RAM". I used this poke often and only lost the screen on my 16k & 64k Coco 2s (Coco 1s may have differed). I have never lost keyboard response. Musica, Bells & Whistles II, Music+, and several other use the 65497 poke for double octave/speed playback, play an entire song, and could come back to normal with a keystroke with ALL memory intact.


-----Original Message-----
From: pfitchjr <pfitchjr at bellsouth.net>
To: 'CoCoList for Color Computer Enthusiasts' <coco at maltedmedia.com>
Sent: Sat, Feb 1, 2020 1:11 pm
Subject: Re: [Coco] Implications of the Speed Up Poke

Remember, there are TWO speed up pokes involved here. One runs ROM at double speed, and RAM at standard speed, and should not be used during input/output. This is the FAST Speedup poke.  (and I guess I'm talking CoCo 1/2 here, as a CoCo 3 in all-ram mode probably wouldn't benefit since there is NO ROM in that mode). The second, SUPER FAST Poke, runs both ROM and RAM at double speed, makes a hash of your video display and stops talking to your keyboard, and that is the one that doesn't refresh RAM.  

So
Poke 65495,0 <--- enters FAST mode
Poke 65494,0 <-- exits fast mode

Poke 65497,0 <---Enters SUPER FAST mode
Poke 65496,0 <---Exits SUPER FAST mode

Tho the suggested commands to exit SUPER FAST mode are actually:

Poke 65497,0 <---Enters SUPER FAST mode
Poke 65495,0 <--- enters FAST mode
Poke 65496,0 <---Exits SUPER FAST mode
Poke 65494,0 <-- exits fast mode

The article I was reading is found in:
Micro-80, Volume 4, Number 3, October 1983, pg 7. I got the copy I'm using off of the Internet Archive, as the TRS-80 Color Computer Archive only has V3N1 atm. ( I guess I could upload the issues I have found to there as well.  I'll do that sometime today.)

-----Original Message-----
From: Coco <coco-bounces at maltedmedia.com> On Behalf Of Allen Huffman

Programs like Musica 2 on a CoCo 1/2 had the option to play music in the fast mode, losing video while the audio played at better quality. I never knew there was any RAM concern as you could play long songs with no issues.

What is the source of the RAM refresh concern?

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