Original Schematics
March 2010 We received several PDF files from Mr. Simon, courtesy of Douglas Goodall which contain the original schematics. Until I extract the images and post them on this page, please click over to the "Documents" tab from the menu and download them from there!
Don't forget to look at my CAD schematics below!
Original Schematics
These were emailed to me, courtesy of Ron Weiss early 2002. They were in JPG format, and are thus pretty grainy in some spots, some of the IC pin numbers are not very legible. I have tried to clean these up a bit and converted them to GIF format here.
This is a pretty amazing design, given the era it was produced in.
It is still a very handy controller and teaching tool.
- IC Layout.
- Sheet 1 of 4 - CPU, Decoding and Z80 SIO (RS-232). 
Errors on this sheet, see below for details.
- Sheet 2 of 4 - Static Ram, J-9 System Interface Connector and Spare Gates.
- Sheet 3 of 4 - Roms, 8255 # 3, 8253 PIT, 8729 Kbd/Displ, 9513 PIT.
- Sheet 4 of 4 - 8255 #1, and 8255 # 2, 9511 Mathbox and J-10 Power Connector.
DXF Format Schematics
- Sheet 1: Printed Circuit Board IC Layout.
- Sheet 2: CPU, Decoding for Memory and I/O.
- Sheet 3: Memory, Rom Jumpering, J-9 System Interface Connector, and Spare Gates.
- Sheet 4: I/O Devices and RS-232 Serial Port.
- Sheet 5: AMD 9511/9512 Mathbox and 9513 Programmable Interval Timer.
Also includes my design for the HD44780 LCD Interface.
My designs for use with this board:
- Sheet 6: Memory Expansion Board.
- Sheet 7: Keyboard/Indicator Lamp 8279 Interface Board.
- Sheet 8: 8255 Discrete Input/Output Interface Board.
- Sheet 9: Lighting Controller [Christmas Lights].
NOTES:
I have produced my own set of schematics using CAD, and provided these files in DXF format for your use. These 11" x 17" sheets (ANSI B size) include my own notes made while building this board which I hope will make it easier to build and easier to understand your Z-80 computer. These DXF files should be compatible with most off-the-shelf CAD programs and file viewers.
In case you don't have CAD, I have sucessfully pasted one of the DXF files into a Microsoft Word document, quite usable although it contained a few minor artifacts and border misalignments.
There are two pairs of discrepancies between the original schematic and the physical board itself.
I found these while trying to wire up the second serial port of the Z-80 SIO.
On Sheet 1 of 4, where IC-2 (Z-80 SIO) connections to J-2 are shown,
the original schematic shows the following pins:
- IC-2.30 - J2.9
- IC-2.29 - J2.8
- IC-2.28 - J2.7
- IC-2.27 - J2.6
- IC-2.26 - J2.5
- IC-2.25 - J2.4
- IC-2.24 - J2.3
- IC-2.23 - J2.1
- IC-2.22 - J2.2
The actual connections are as follows:
- IC-2.30 - J2.9
- IC-2.29 - J2.8
- IC-2.28 - J2.7
- IC-2.27 - J2.5
- IC-2.26 - J2.6
- IC-2.25 - J2.3
- IC-2.24 - J2.4
- IC-2.23 - J2.1
- IC-2.22 - J2.2
I have corrected this in my DXF format schematic drawings.
Sheet 5 [SH 5] has the 9511/12 and 9513 IC schematic. Since these IC's are very rare, I have used the 9511 socket at IC-17 to install my LCD display interface; this interface schematic is also on Sheet 5 as well as the original information.
I've put a lot of work into these schematics, and I believe them to be very accurate and of the highest quality. If you spot an error or have a question about them, please drop me a line and let me know.
Enjoy!
This page created January 27, 2006.
