Re: BASIC and System ROM replacements

From: Gerrit Heitsch <*gerrit_at_laosinh.s.bawue.de*> Date: Wed, 29 May 2013 16:55:27 +0200 Message-ID: <51A616DF.5010002@laosinh.s.bawue.de> · gerrit_at_laosinh.s.bawue.de

On 05/27/2013 07:57 AM, Baltissen, GJPAA (Ruud) wrote:
> Hallo JG,
>
>
>> Something I'd find useful is being able to have more than 16K
>> available in the 16K cartridge slot, and to be able to page
>> the cartridge out. Then I could copy greater than 16K code
>> from the cartridge to RAM, than page out the cartridge.
>
> A 27512 EPROM can handle 64 KB. A 74LS273, a resetable latch, can handle the pages plus 'paging out' the cartridge.

Another useful TTL in that respect is the 74LS175. It's used in the 
banking logic of the 264 series. It only has 4 Bits instead of 8 but all 
of them are available as normal and inverted.

  Gerrit

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