mega drive computer

[gist]

hey, what are the specs on the mega drive computer clone that is posted on the main page?

is it strictly a japanese or europe computer? cause i haven't seen any of those in the US

the only similiar mega drive that's close to that one is the blackish case one with the 286 pc inside of it. looking at yours, it must have been made later, for it has a 486 inside. What an excellent collector's item!

[oompa loompa]

specs of my genesis computer (doesn't have a name =P):
- Include all genny specs here, eg: has a Motorola 68000 main processor, Z80 co-processor, 64k working RAM, 64k video ram, etc etc
- Clock can be switched to and from 7.7 mhz, 12.0 mhz, 13.4 mhz, and 18.384 mhz (the last two are only used for code that doesn't use the vdp, like the 68k assembler)
- There is 4 mb of main program ram that is bankwitched in memory mode I
- RS232 UART with a maximum baud rate of 115200bps
- 20 gig IDE harddrive 0.o!
- Has an RTC to keep track of time and to hold the operating system settings, big woop =P
- 256k of flash rom memory for bootstrap + os
- You can type stuff to it using a ps/2 keyboard
- Has an external ISA bus that can interface network cards, serial cards, parallel port expansion cards, programmable i/o cards, everything that doesn't have to be accessed by memory (like vga cards)
- in addition, the operating system extends the computer to do some fun stuff like play all the sega genesis games ever made, play 8 bit mono wave files wow, interpret basic programs, edit text files, assemble 68k assembler code, draw using a 31 color pain program, and whatever else it has on it

the computer isn't manufactured by a company, it was all made from scratch by me. there is no 486 main processor controlling the sega motherboard either

[GiGaBiTe]

be cool if you could post the engineering notes, and maybe some blueprints so others can build a genny computer.

[oompa loompa]

sometime later =D

[GiGaBiTe]

instead of overclocking (and posibly burning out the cpu) why dont you get a MC68030 in pga format? there are so few pins on it, that you could make a socket for it and solder wires to the different pins and make an adpater.

a 33 MHz 68030 talk about a screaming genesis XD. could probably implement some bastardized PCI slot also and put a good video card in lol.

[paulpsomiadis]

68030 is a different instruction set..so it wouldn't be possible!

But I HAVE heard of a Genny with a 68010 in it...and even that one was less compatible than an OC'd Genny!

[GiGaBiTe]

all 68k's are compatible with eachother, and why wouldnt they be, they are the same architecture. there is however the exception of the 68060, i dont think it likes 16 bit code. (purely 32 bit)

so its pretty safe to say that even a 68040 can run 68000 code. you would probably have to start creating busses that run at the old cpu speed (7.68 MHz) so that the vdp and everything else dont go insane from the speed.

you can also run code from a newer 680x0 on an older 680x0 (not counting the 040 and 060) but its likely it would be incredibly slow.

now something you couldnt do is run PPC code on a 68k chip. for obvious reasons, the PPC has 32 address and data lines while the 68k only has 7 of each.

[adamlips]

Hi there, Its my first time here so before I go on - What a great site and great forum. Now on to your "hyper" drive (well its certainly beyond mega now!!!) would be willing to share the information on your ram board and hard drive interface? at the moment I use a Totek flash cart and have to do a lot back and forthing, it would be great to have a hard disk and your wonderful basic stored on there.

[GiGaBiTe]

do some forum digging, im pretty sure he posted a schematic on how to interface an ide hard drive to a genesis. i know for a fact that he showed it was possible to use 4 ide drives on the same chain on a genesis, its most likely there.

if you make an IDE controller, might want to use another cpu (6502) to control it because you will eat up a ton of 68k power doing data transfers..