cross-post:fpga-cpu upcoming events ibm1130

woodelf bfranchuk at
Tue Oct 16 18:00:43 CDT 2007

--- In fpga-cpu at, woodelf <bfranchuk at ...> wrote:
 > >
 > > rtstofer wrote:
 > >
 >> > > In the end, the only goal is to get Unix V6 running.  Just because...
 >> > >  I don't have any long time love affair with PDP's.  That level of
 >> > > commitment is reserved for the IBM 1130.
 > >
 > > Then why are you *NOT* doing that in a FPGA?
 > >
 >> > > Richard
 > > Ben.
 > > PS. Ok the hard drive, line printer and punch card
 > > card reader/punch don't fit in one.Other than I/O
 > > the IBM-1130 had a nice instruction set considering
 > > the time era it was in.
 > >

But, I already have...  The FPGA implementation runs the entire IBM
software suite include DMS, Fortran, Macro Assembler, etc.  Even
Robert Louden's "Three Dimension Tic-Tac-Toe" is running.

In the beginning I used a 25x80 VGA display core for the console
printer, a PS/2 keyboard core for the console keyboard and a pair of
serial port cores for the reader and printer.

I got lazy and loaded the OS on a 16Mb flash EEPROM and copied it to
RAM for a ram disk.  That limited the system to 16k words versus a max
of 32k.  I have started working on an IDE interface for one or more CF
drives.  I have always viewed that as a 'someday' project because
source code was never stored on the disk.  Building programs from
source decks is more interesting to watch if the disk is 'fresh'.

It's been running for several months and I will do a "show and tell"
at the Vintage Computer Fair, Nov 3rd, at the Computer Museum in
Mountain View.  There's a 5th annual IBM 1130 party at the fair.

For that evolution, the console display and keyboard will be replaced
with yet another serial port so that there will be 3 instances of
Hyperterminal running on a laptop (ugly...).  Portability drives the

I like the IO system: it is all based on DMA and if you want to add a
gadget, just hook it up to the DMA channel, invent an XIO command
sequence and write the driver.  I only implemented the devices that
used DMA like the 2501 card reader and 1403 printer.  I added delays
so that the IO devices run in real time.

The IBM 1130 is the first computer I ever used, starting in 1969.
There are a few 'firsts' in life that are worth remembering; this is
one.  Fortunately, there were others...


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