Date   : Tue, 19 Jul 2011 17:13:24 +0100
From   : jgh@... (J.G.Harston)
Subject: Emulating the 80186 CoPro on an ARM CoPro

Sprow wrote:
> Isn't the 80186 the Tube that uses DMA? The FPGA doesn't have the DRQ/DACK
> lines wired anywhere nor any logic to support it, so if it does use DMA for
> something then the ARM copro is going to come unstuck.

Yes, I think you'd have to emulate the Tube API rather than the Tube
interface itself, a bit like 65Tube, Z80Tube and PDPTube.

(ie, instead of STA TubeR1, etc., you co-opt some undefined opcodes
and use them to do EQUB MOS_FILE, MOS_MEM, etc.)

-- 
J.G.Harston - jgh@...