Possible MSX Kickstart Project ?

Resident (45)

30-01-2015, 10:44

I'm thinking of doing a 'Kickstart' project for a self-build MSX+ Computer :

specification
MSX 2 compatible:

Z80 CPU (switchable between 3.58MHz and 14.32MHz)
512K + RAM
256K ROM
V9958 Video 192K VRAM
AY-3-8910 PSG
YM3812 PSG
PS/2 keyboard
Floppy Drive
IDE Hard Drive
CF Card reader
RS232 Port
Parallel Port
Expansion Bus

It Would be made as a Self-build DIY kit, to build and test yourself. Hopefully selling for $150

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Van x-nen Aivalahostia

Paragon (1563)

30-01-2015, 12:10

Why not an msx2 or turboR compatible?

Van alexworp3

Expert (126)

30-01-2015, 12:43

why not a faster but softwarecompatible vdp.
Why a ide hdd and not a scsi
why not an opl4 compatible soundchip

Why not a real msx3?

am I asking stupid questions now?

Van Dirty Harry

Resident (45)

30-01-2015, 13:12

It's cost, I'd have to make something relatively cheap..if I put all the bells and whistles on it, then it would end-up more expensive than the Homer Simpson car ( Remember the one that cost $87,000) !

Also it would need to be relatively easy to build and test, otherwise no one would buy it !

Van flyguille

Prophet (3031)

30-01-2015, 13:53

512K + RAM ?

I hope that means 2MB or the theorical maximun of 4MB in one slot/sslot (without breaking the msx2 standard).

Van st1mpy

Paladin (947)

30-01-2015, 14:31

personally, I have no interest in soldering all those components just to get a msx...
if its ready made and nice case and nice mechanical keyboard, yes pls.

Van raymond

Hero (653)

30-01-2015, 20:05

Sounds like a good idea!

Van Grauw

Ascended (10821)

30-01-2015, 23:00

I would be interested, if it comes with a good manual . The specs sound good to me, and the project seems educational and affordable.

However, before I spend money I’d require some assurance the project will complete. For example, to see a working prototype, some preliminary documentation, and a summary of the cost of the parts to show $ 150 is feasible. I need to understand how it can be so much cheaper than GR8BIT…?

Van Dirty Harry

Resident (45)

02-02-2015, 15:39

A similar system to the MSX has already been done here : (Prototype)

http://primrosebank.net/computers/mtx/projects/mtxplus/mtxpl...

This is called the MTXplus+ though similar (very Similar) it is not the same, but proves it can be done.

Draft cost have been done : MSx plus

Z80 CPU (switchable between 3.58MHz and 14.32MHz) $2.0
512K + RAM 128K SRAm $1.0 each, DS1250 NVSRAM 512K $2.0 each
256K ROM W27C020 $1.0 each
V9958 Video 192K VRAM $5.50 each + DRAMs + PAL/NTSC encoder (total $10.0)
AY-3-8910 PSG $1.70
YM3812 PSG $1.50
PS/2 keyboard ( microcontroller Atmel etc $1.0)
Floppy Drive FDC IC $7.50
IDE Hard Drive IC 82C55 $2.0
CF Card reader 82C55 $2.0
RS232 Port Z84C4010 $2.0 each
Parallel Port 82C55 or similar $2.0
Expansion Bus $5.0

All the IC should be less than $40 , these will be a combinatiion of working Pulls and NOS to keep costs down ! Brand NEW ICs would simply be Too expensive.

The PCB will be the most expnsive part , hopefully this should cost less than $50 each
Connectors, D-types, PS/2 keyboard, DIN etc $10
Cartrige Slot ?? yet to be costed
Resistors / Diodes, switches etc $15

This is just a DRAFT costing but does give some idea.

Van anonymous

incognito ergo sum (116)

02-02-2015, 18:07

alexworp3 wrote:

why not a faster but softwarecompatible vdp.

Because such a thing doesn't exist.

alexworp3 wrote:

Why a ide hdd and not a scsi

Because IDE devices and adapters are easily available, SCSI not so much.

alexworp3 wrote:

why not an opl4 compatible soundchip

Because that's not MSX.

alexworp3 wrote:

Why not a real msx3?

Because a real, official MSX3 standard would require the support of the current rights owner, and lots of serious full time work.

alexworp3 wrote:

am I asking stupid questions now?

Yes.

Van syn

Prophet (2135)

02-02-2015, 19:10

YM3812 is not a psg thats a opl2. Do you plan to use it as a replacement for YM2413/opll/msx music? I dont how how this will work out?

192K vram is not really needed.. afaik there is zero software for that. Basic msx2/2+ is 128KB

You have a v9958 why not call it msx2+ compatible? (your first list mentions msx2 compatible only.)