Ron61 & Excaliber, you are no longer tops!

[patrickt]

Originally Posted by PaulProe

... maybe I should ask him to explain Vroom-Vroom.

Mostly I just enjoyed bugging Rick P. with my answer.

[Ronbo]

16 bits? 8088 was an 8 bit processor, like it's cousins the 8080, Z80 and the guy across the tracks, the Motorola 6800.

You guys would be suprised how many industrial controls out there are still running Z80's. Even as we speek there are thousands of Z80's and 6800's dilligantly making sure your "lumpy" water makes it to the sewer plant.

Sorry, couldn't resist a chance to get my post count up.

[patrickt]

Originally Posted by Ronbo

16 bits? 8088 was an 8 bit processor, like it's cousins the 8080, Z80 and the guy across the tracks, the Motorola 6800.

No, Ronbo. The 8088 microprocessor has 16-bit registers, 16-bit internal data bus and 20-bit address bus, which allows the processor address up to 1 MB of memory. The 8088 uses the same segmented memory addressing as the 8086: the processor can address 64 KB of memory directly, and to address more than 64 KB of memory the CPU has to break the update into a few parts - update up to 64 KB of memory, change segment register, update another block of memory, update segment register again, and so on.

Source: http://www.cpu-world.com/CPUs/8088/

[Ronbo]

OK you got me going, I'll have to dig a little.

The link you posted doesn't state the instruction set used. Far as I remember the 286 was the first true 16 bit CPU in Intel flavor.

My bad, it's on the "architecture" page, 16 bit instruction code...

[patrickt]

Originally Posted by Ronbo

Far as I remember the 286 was the first true 16 bit CPU in Intel flavor.

No, the 8086 was a true 16 bit processor, the 8088 dropped the external bus width to 8, but was still 16 bit in every other way. Perhaps you're thinking of the really old 8008, which was 8 bit. The 286 had the ability to address 16 megs of memory by kicking the processor in to protected mode, but hardly anything was written in PM back then. What you could do (and you might remember this) was to referece the first 64k of extended memory even though you were in real mode. You did this by opening the A20 gate and then using a segment register loaded with FFFF to address the memory. It was called the "High Memory Area" and you used to load himem.sys to do that and "Load DOS High." Coming back to you yet?

[xlr8or]

Originally Posted by patrickt

No, the 8086 was a true 16 bit processor, the 8088 dropped the external bus width to 8, but was still 16 bit in every other way. Perhaps you're thinking of the really old 8008, which was 8 bit. The 286 had the ability to address 16 megs of memory by kicking the processor in to protected mode, but hardly anything was written in PM back then. What you could do (and you might remember this) was to referece the first 64k of extended memory even though you were in real mode. You did this by opening the A20 gate and then using a segment register loaded with FFFF to address the memory. It was called the "High Memory Area" and you used to load himem.sys to do that and "Load DOS High." Coming back to you yet?

Remember the MFM drive / RLL controller combo to fake it into thinking the drive was bigger. Got that 40MB disk to look like 60 then put stacker on it and got about 85. It only crashed about once a month.

Ok Stop. The flash back are killing me. I'm going to have to go to bed and reboot.

[wtm442]

Hey
I'm going to report a blatent case of thread hijacking here to discuss the half life of electrons flowing thru silicon.

OK, now where did I put that box of punch cards so I can finish this post. Boy, do I wish my IBM 360 was back from the repair shop.