Extended cpu carts

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بواسطة Leo

Paragon (1236)

صورة Leo

22-02-2010, 14:44

in fact you d like a Lpe-z380-v2 cart to be twice the speed and 4x times cheaper !!!
i was just reading the architecture of that card is compatible with eZ80 , but see after so many years it has not been so much used.
The most simple is to buy that Z380 card , if you think you have that amount of money to put into , on top of that it is able to emulate
the game boy with GEM so no need of gameboy player cart ...
it is hard for me to put 210 euros that card , id like to but it is a bit too much , and ram is not included , nice piece of hardware tough,
very nice ......

بواسطة Leo

Paragon (1236)

صورة Leo

22-02-2010, 23:50

i wrote this little doc , based on what i can imagine :
http://iledefra01.free.fr/msx/co-pro.pdf

the data transfer will be on I/O port , 128kb SRAM , 16kb bios , SD interface for almost free.

بواسطة Leo

Paragon (1236)

صورة Leo

28-02-2010, 10:07

looks like this guy did a fast Z80 coprocessor for pc-88:
http://expert-2.hp.infoseek.co.jp/pc88/kairo.png

بواسطة msxegor

Master (183)

صورة msxegor

19-03-2010, 09:14


- fpga is the most expensive way to do Z80 or other cpu , what about using regular Z80 4MHz just
for protyping , just to see how it would work for data transfers .

a Z180 is good for that ?
IDT7007 is a 32kx8 dual port sram

Actually modern FPGA that is large enough for Z80 (~2500-3000 cells) is about 3 times cheaper than 33 mhz Z180 Smile
Even if you add a configuration device, power regulators and logic level shifters it will still be on par with Z180
Fast SRAM is also not a problem - there are plenty 20, 15 and even 10 ns 512K devices (about a month ago i bought
a couple of the cheapest SRAMS i could found in stock - and to my surprise they were 10 ns!)

بواسطة Leo

Paragon (1236)

صورة Leo

19-03-2010, 22:46

i got a stock of Z280 for 3 us dollar each, cheaper than some 74LS's !!!

fpga are starting t 15usd the smallests ( spartan 3A ) inside of which you can only fit a z80 vhdl plus a few things.
fpga are in BGA or TQFP package , you need special equipment to solder them or subcontract the board. $$$$... Hobbyists dont do their fpg card , they use card like DE1 or others ... hundreds $$$$....
OR you can buy fpga modules , nothing is below 40usd , and usually 100usd if you want RAM with it flash and decent DIP connectors .then you still need pcb plus ics , you can easily reach 70 euros, all in all.

Z380 dont have vhdl models , yet .
How much do you get Z180 33MHz ? i could get a quote on my side as well.

بواسطة msxegor

Master (183)

صورة msxegor

20-03-2010, 07:37

i got a stock of Z280 for 3 us dollar each
That's because the part is obsolete. (that's a shame, Z280 is the greatest processor Zilog made, would like to make an accelerator for MSX)

fpga are starting t 15usd the smallests
How much do you get Z180 33MHz ? i could get a quote on my side as well.( spartan 3A )
Searched Digi-Key, Z180/33 in PLCC is $15.50, Altera Cyclone EP1C3 is about $10 - still cheaper Smile
Our local price is $11.50 for that Cyclone and $45 for Z180 (!!!!)

fpga are in BGA or TQFP package , you need special equipment to solder them or subcontract the board.
QFP is not that horrible, you even can etch a board at home.
i2.fastpic.ru/thumb/2010/0311/88/eed6d7984f57db0d78c49b9acbf41888.jpeg
Anyway you have to subcontract boards if you wish to make more than a few of these carts.

Z380 dont have vhdl models , yet .
Actually, Z380 is designed in Verilog :)
I'm thinking of upgrading T80 vhdl code to support Z380 instructions, but that's a long story

PS.
If you want to make a fast sub-processor you may look at Z80382 also - has nice features for inter-processor pipe built-in.

بواسطة Leo

Paragon (1236)

صورة Leo

20-03-2010, 08:18

Yes Z280 is great , it can :
execute R800 instructions.
i have hitech-c version for Z280
it has cache and so work 6.25MHz external while being 12.5MHz internally , which is nice for max.
but :
its data 7-0 and address 7-0 are multiplexed , not a big deal with a 8bit latch.
and worst it M1 pin is only active on RETI instructions ! so wait states generation
in MSX is a problem , think about 6MHz bus 0 wait state and memories running at 250-300ns !!
...
This board is for MSX ? is it an SD interface you made ? omg !!!! look at the resistors , how on earth did you solder so many !!!!

بواسطة msd

Paragon (1510)

صورة msd

20-03-2010, 10:36

one of my msx'es runs fine without the m1 wait Tongue

بواسطة msxegor

Master (183)

صورة msxegor

20-03-2010, 11:25


This board is for MSX ? is it an SD interface you made ? omg !!!! look at the resistors , how on earth did you solder so many !!!!

No, that's not mine SD interface (i have to finish it yet) This is built by local msx freak
The board is auto-loading cartridge simulator (loads ROM from SD, configures FPGA as appropriate mega- or rom mapper - and go)

بواسطة Leo

Paragon (1236)

صورة Leo

20-03-2010, 11:38

one of my msx'es runs fine without the m1 wait Tongue

really ? what is the acces time rom/Rams ?
actually there is a way to program a wait state generator inside Z280 , but it requires one external ic , during reset some value has to be forced on databus.

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