If I was building a PC for early 80's CGA gaming is there really any benefit with going for a 8086 based system over an 8088? would one encounter any compatibility issues with a 8086, speed issues such as games running to fast? are there any games/applications that work on a 8086 but not a V30?
the 8088 is a variant of the 8086, but with an 8bit external bus, instead of the 16 bit ext bus found on the 8086s, and a smaller prefetch queue. It'll work, but depending on the instruction order, you may see some performance loss with the 8088. The Execution units are identical between the two, though.
*EDIT*
And why CGA? You can use EGA and CGA mode on the 8086 with a compatible EGA monitor and EGA card. I used to, when I got my first 8086. Half the games I was given at the time used CGA, whlie others used EGA.
*EDIT 2*
As far as speed issues, you can use utilities like MoSlo (if it's still around) or others, that'll throttle the machine down to real mode x86 speeds.
*EDIT 3*
The NEC V30 is a pin compatible reverse engineered 8088/8086 compliant part that also supports the 80186 instruction set. Even IBM used them in certain PS/2 models, so I don't forsee any compatability issues. That said, I've never used a V30, so take that with a grain of salt.
wrote:And why CGA? You can use EGA and CGA mode on the 8086 with a compatible EGA monitor and EGA card. I used to, when I got my first 8086. Half the games I was given at the time used CGA, whlie others used EGA.
I don't think it is is quite perfect emulation.
Huh. Well, I was admittedly a 10 y/o kid when I first used that PC, so it seemed accurate enough for me, but I could always be mistaken.
wrote:Huh. Well, I was admittedly a 10 y/o kid when I first used that PC, so it seemed accurate enough for me, but I could always be mistaken.
Some games that used the more obscure features would act up on anything newer.
Here is a tester: http://www.oldskool.org/pc/cgacomp
Which games are you planning on playing that use those features? I just used sierra online games, and some random games that came as batch files on floppy disks. Like the text star trek game, rogue, and some pretty poor arcade ports, so those may not have used the obscure features you're talking about.
I don't have any specific games in mind just really early stuff and smeezekitty hit the nail on the head with CGA, its because of those games that may use more obscure features. for EGA stuff I have a 286 and a 386 machine. I also don't like using slowdown programs like moslo, yes I guess i'm one of those insane purists or I just kick a bizarre kick out of the novelty of not having to.
I guess to restate the goal. I want the fastest most compatible machine for really early CGA stuff. If a 8086 will get me the same compatibility but they games will play smoother because of a small speed increase i'll go with that but if a 8086 will cause some stuff to play to fast i'll just go with an 8088.
The real experiment would be to buy an IBM 5150. I have used 8086s (IBM PS/2 Model 30 8086) and a V30 (installed in IBM PS/2 Model 80 8086). Granted: These machines have MCGA but they are slow as molasses. But King Quest et al run on them. Civilization also runs but very slowly as does Operation Wolf for example.
This is another nice OEM 8086: http://www.vintage-computer.com/vcforum/showt … E-8086-Computer.
The IBM 5150 is just a regular original IBM PC. For some reason, they included it in the 5100 series, which were a totally incompatible architecture. Go figure... 😒
The IBM 5150 was the #1 PC for many years. The 5160 is also pretty interesting as is the 5170. Especially when coupled with an IBM 5153/4.
I actually have a 5150 here i'm restoring but its missing any drives. I basicly just have the case and motherboard. I actually PMed the seller of that Epson machine last night but as yet no reply. 🙁
