newbie building a scratch-built computer

[Allison]

>
>Subject: Re: newbie building a scratch-built computer
>   From: ard at p850ug1.demon.co.uk (Tony Duell)
>   Date: Sun, 05 Aug 2007 21:21:07 +0100 (BST)
>     To: cctalk at classiccmp.org
>
>[EPROM emulatoros]
>
>> *) Maybe your and my programming strategy differs; now with SW emulators
>> for almost any old CPU being available ona PC, I tend to test my code in
>
>It does. Remember I don't have anything that will run such an emulator at 
>anything like a reasonable speed.

For test reasons often not a requirement to run at near real speeds.
Sometimes slower is good for testing, most sims can do things even 
a hardware front pannel would envy. Usually I use a spare 486dx/66, 
certainly not lightining fast but enough to test to see if the code
even runs and usually decently fast.  the P1mmx/166 I use for email
and stuff runs Myz80 and Dunfields NS* Horizon (4mhz z80) and 
CUBIX (6809) SIMs all run close to or better than real speeds.
Thats good enough considering the tools they provide as an offset 
if any.

>Anyway, I like to write little test programs to run on the target 
>hardware (maybe just outputing a message through the serial port, or 
>blinking some LEDs, or...). Just to make sure the target is doing 
>something sensbile.

I prefer to run on hardware too but, there are times when a my 486/75
laptop is at hand and I'm way from my bench so why not?


Allison