Date   : Thu, 26 Jan 2012 15:09:09 +0000 (GMT)
From   : info@... (Sprow)
Subject: CRC-8 algorithm

In article <c873124d282edbcf6f03e50d201aa07b@...>,
   J.G.Harston <jgh@...> wrote:
> I have a need for an 8-bit CRC algorithm (transmitting up to about
> 20 bytes, CRC-16 would be overkill, and I'd prefer a CRC rather
> than a checksum).

Would the one in the BBC micro tape filing system be suitable?
Pasted from my RFS ROM formatter, RFSHead, line 1710:

.calccrc
 LDA#0:STAcrcH:STAcrcL:TAY
.next
 LDAcrcH:EOR(vL%),Y:STAcrcH
 LDX#8
.again
 LDAcrcH:ROLA:BCCover
 LDAcrcH:EOR#8:STAcrcH
 LDAcrcL:EOR#16:STAcrcL
.over
 ROLcrcL:ROLcrcH:DEX:BNEagain
 INY
 CPYlength%:BNEnext
 LDXcrcH:LDYcrcL:RTS
.crcL
 EQUB0
.crcH
 EQUB0 

Sprow.