Zeta SBC - Minimal, self-contained, N8VEM compatible Z80 SBC

[Sergey]

Zeta SBC is an easy to build Zilog Z80 based single board computer. It
is inspired by Ampro Little Board Z80 and N8VEM project. Zeta SBC is
software compatible with N8VEM SBC and Disk I/O boards. This is an
open source project: all design files (KiCad schematics and PCB,
Gerber) are available from N8VEM Wiki.

Here are the specifications:
- Small form factor (170 mm x 100 mm, 6.7" x 4"), can be mounted under
a 3.5” floppy drive.
- Through hole components only, most of the components are pretty
common (a good way to get rid of some stuff in your junk box).
- CPU: Zilog Z80. It was tested with NMOS and CMOS versions, up to 20
MHz, 6 MHz or greater is required to support 1.44MB floppies.
- Memory: 512 KiB SRAM (system + RAM disk) with DS1210 NVRAM
controller, 512 KiB flash (BIOS, CP/M, ROM disk)
- 8255 PPI. Can be used to connect an IDE hard drive or CF card using
PPIDE adapter, or for just generic I/O.
- 16550 UART. Serial port for connecting a terminal.
- FDC9266 or FDC9268 floppy disk controller, supports common (that is
IBM) diskette formats.
- DS1302 RTC.
- Runs CP/M 2.2 and ZSDOS, ROM images are available from N8VEM Wiki.

More information please refer to this page:
http://n8vem-sbc.pbworks.com/w/page/44366173/Zeta%20SBC

I offer PCBs and some (more difficult to find) ICs in any combination.
Prices: PCB - $20, FDC9266 - $5, Z84C0020PEC (CMOS Z80 CPU, 20 MHz) -
$5, Toshiba TMP82C55AP-10 (CMOS 8255 PPI, 10 MHz) - $4, SST39SF040
(512 KiB flash, preprogrammed with BIOS, CP/M, and some utilities on
the ROM disk) - $4.

Shipping (one PCB and up to 4 ICs using USPS First Class mail, no
tracking) is $3 in US and $6 anywhere else.

Thanks,
Sergey

[Peter Dassow]

Post by Sergey
Zeta SBC is an easy to build Zilog Z80 based single board computer. It
is inspired by Ampro Little Board Z80 and N8VEM project. Zeta SBC is
software compatible with N8VEM SBC and Disk I/O boards. This is an
open source project: all design files (KiCad schematics and PCB,
Gerber) are available from N8VEM Wiki.
- Small form factor (170 mm x 100 mm, 6.7" x 4"), can be mounted under
a 3.5” floppy drive [...]

Hello Sergey,

look really interesting or better promising.
What I missed is an integrated video controller and keyboard interface.
I do not like to connect a (CP/M) computer to a PC just to get a display
(so I have to use a much bigger computer just for display and keyboard
input....).
It would be *very* nice to have a Z80 based computer "all in one",
except the floppy disk drive, the (VGA-) monitor and the (PC-) keyboard.

Regards
Peter

[Sergey]

Hi Peter,

You're right, and for my next project (if and when I'll have time). I
am thinking about integrating a Propeller chip as a VGA and keyboard
controller. That perhaps instead of the FDC chip - storage can be
replaced using an SD card connected to the Propeller.

But even now you don't have to use a PC. It is possible to use a real
terminal (if you have one), or a PockeTerm (http://
www.brielcomputers.com/wordpress/?cat=6).

Best regards,
Sergey

Post by Peter Dassow

Post by Sergey
Zeta SBC is an easy to build Zilog Z80 based single board computer. It
is inspired by Ampro Little Board Z80 and N8VEM project. Zeta SBC is
software compatible with N8VEM SBC and Disk I/O boards. This is an
open source project: all design files (KiCad schematics and PCB,
Gerber) are available from N8VEM Wiki.
- Small form factor (170 mm x 100 mm, 6.7" x 4"), can be mounted under
a 3.5” floppy drive [...]

Hello Sergey,
look really interesting or better promising.
What I missed is an integrated video controller and keyboard interface.
I do not like to connect a (CP/M) computer to a PC just to get a display
(so I have to use a much bigger computer just for display and keyboard
input....).
It would be *very* nice to have a Z80 based computer "all in one",
except the floppy disk drive, the (VGA-) monitor and the (PC-) keyboard.
Regards
  Peter

[Peter Dassow]

Post by Sergey
You're right, and for my next project (if and when I'll have time). I
am thinking about integrating a Propeller chip as a VGA and keyboard
controller. That perhaps instead of the FDC chip - storage can be
replaced using an SD card connected to the Propeller.
But even now you don't have to use a PC. It is possible to use a real
terminal (if you have one), or a PockeTerm (http://
www.brielcomputers.com/wordpress/?cat=6).

A terminal is also an extra device (can be really bulky if it's an older
one), and at least it's slower than a memory mapped display when
scrolling etc. But PockeTerm looks quite nice.
May be you can establish something like a bus system to connect an extra
display card of your own ;-)

(That means reinvent the computers of the "Eighties" ,-) ... )

Regards
Peter

[Sergey]

For that you have the N8VEM project (http://n8vem-sbc.pbworks.com/)
that offers entire range of boards based on ECB bus. Also there is a
similar project for S-100 bus based boards (http://
www.s100computers.com/). I don't want to replicate their effort
(although I am contributing to the N8VEM project). The idea of Zeta
was designing a minimal, easy to build, but yet interesting Z80 based
single board computer, featuring most components early 80's computer
would have. I designed it to be hardware compatible with N8VEM SBC and
Disk I/O boards, so the same software (BIOS, utilities) can be used on
both systems.

Best regards,
Sergey

Post by Peter Dassow

Post by Sergey
You're right, and for my next project (if and when I'll have time). I
am thinking about integrating a Propeller chip as a VGA and keyboard
controller. That perhaps instead of the FDC chip - storage can be
replaced using an SD card connected to the Propeller.
But even now you don't have to use a PC. It is possible to use a real
terminal (if you have one), or a PockeTerm (http://
www.brielcomputers.com/wordpress/?cat=6).

A terminal is also an extra device (can be really bulky if it's an older
one), and at least it's slower than a memory mapped display when
scrolling etc. But PockeTerm looks quite nice.
May be you can establish something like a bus system to connect an extra
display card of your own ;-)
(That means reinvent the computers of the "Eighties" ,-) ... )
Regards
  Peter

[Peter Dassow]

Post by Sergey
For that you have the N8VEM project (http://n8vem-sbc.pbworks.com/)
that offers entire range of boards based on ECB bus. Also there is a
similar project for S-100 bus based boards (http://
www.s100computers.com/). I don't want to replicate their effort
(although I am contributing to the N8VEM project). The idea of Zeta
was designing a minimal, easy to build, but yet interesting Z80 based
single board computer, featuring most components early 80's computer
would have. I designed it to be hardware compatible with N8VEM SBC and
Disk I/O boards, so the same software (BIOS, utilities) can be used on
both systems.

Post by Peter Dassow
May be you can establish something like a bus system to connect an extra
display card of your own ;-)

You're right with S-100 bus (or even ECB).
But my idea is similar to your own... create a single board computer
with all (important) I/O devices without a bus system, but let me decide
if I want to get also an integrated VGA and keyboard interface or not.
So may be it could be implemented as an option (as a piggyback board)
with an internal connector (not usable as a generic I/O plane, but for
this "upgrade").
As a result, it should be a board w/ or w/o VGA and keyboard interface,
depends what stage of expansion you choose.

Just my 2 cents...