The 8500 only has P0-P5 bonded out. I've not seen an 8501 die shot, but I assumed the 8 bits were all there and they only bonded out P0-P4 & P6-P7. It had to fit in a 40 pin chip and they also dropped NMI & Phi2 out. It would have made more sense if the 6510/8500 bonded out P0-P3 & P6 & P7, as you could use N & V flags after an LDA for branching based on P6/P7 without any comparison instruction required. On 27/12/2016 18:14, Gerrit Heitsch wrote: > > > Anyone wants to compare the 8500 and the 8501? Now you can... > > https://siliconpr0n.org/map/mos/8500r4 > > > I would really like to know why they removed port bit 5 from the 8501 > while the 8500 has all 8 port bits them. > > Gerrit > > > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2016-12-28 13:00:02
Archive generated by hypermail 2.2.0.