Sun 4/60 SPARCStation 1

Over the past couple of weeks I have worked to reconstitute a Sun Sparcstation 1 (aka Sun 4/60) that I procured from UW Surplus way back in 1999, and which had been sitting on a shelf since then. The label on the front says it was priced at $0.00, however I think that was just the label the originating department slapped on it – I actually paid $18.99, tax included.

The disk drives had both died, but a SCSI2SD board (both V 5.2 and V6 / 2021) worked as substitutes, with little difference in performance. I set up both SunOS 4.1.4 (aka Solaris 1.4) and Solaris 2.7 (aka Solaris 7) – but the performance of the later Solaris was nearly intolerable. The video card that came with it was has a very odd Sun specific monochrome output, but I was able to acquire a color card at low cost off of eBay this year, and swap them out.

The machine has two Ethernet ports – one on the mainboard (le0) and the other on an SBus expansion board (le1) – the latter has a coax “thin net” connector. I don’t have that, but fortunately I have a couple of AUI cable to 10BaseT adapters so I was able to hook it up to my network.

These systems used a Mouse Systems optical mouse – and I got a mouse with the system, but not the mouse pad – and the pads are now essentially made of “unobtanium”. I found a site on the web where someone had printed their own – dark red horizontal stripes and vertical blue ones. It does not work very well, but at least it does work.

Somewhere along the line I also got a Sun SCSI cartridge tape drive shown in this photo. I have used that with PCs to recover cartridge data, but in this photo it is just for show.

For more info, including links to the PDFs I used to create the mouse pad, visit my UNIX® workstations page.

IBM 1410 FPGA: Posted to Github

The last 12 months I have been pretty busy working on my 1410 in FPGA project, and there is now more to share, though I have not done much actual work since February – been too busy playing with other “toys”.  8D

First, I finished working through all of the IBM 1410 and IBM 1415 Automated Logic Diagrams – generating VHDL and testing the results with test benches.  [Note that this includes the built-in 1401 compatibility mode, activated at the flip of a switch.] That took most of 2020.

So, the CPU generation in VHDL is now more or less complete, and I added a hand coded memory module for memory, as core is kind of hard to find on an FPGA development board.  😉  I am currently using a Digilent Nexys 4, but I think it might have even fit on a Nexys 2 – there is plenty of room to spare, and there isn’t anything in the VHDL aside from, maybe, the memory implementation (though even that is pretty generic VHDL).

With this the CPU runs, at the very least, Unconditional branch (Jump), Halt, NOP and Set Word Mark instructions seemingly correctly – I haven’t tried any others.  Somewhat surprisingly, aside from issues with the hand coded VHDL in triggers and the need to communicate pins tied to logic one or zero, the auto-generated VHDL works untouched.

I have updated the github repository for the C# database application that generates the VHDL from time to time (and which includes the complete database) at

There is now a *new* repository, which holds the generated VHDL, some hand coded VHDL modules for certain SMS cards (typically for triggers, for example), the console and test benches I used along the way, and VHDL “Integration Tests” which are designed to be loaded onto the board – the current one being IntegrationTest3.

There will be, eventually, a third repository which will contain the C# code that “hosts” the IBM 1410 console and peripherals, communicating with the FPGA over a high speed serial over USB connection.  I figured out that this should allow me to emulate peripherals without having to resort to sending data over Ethernet, SPI, I2C or the like.  I have just started that, so it really isn’t at a point that there is much to share.

Once I have a console working (which will require a re-do of the console VHDL implementation, which right now communicates in ASCII, but should probably be using BCD), I should be able to pre-load into memory some of the CPU diagnostics, by loading a diagnostic routine into either my 1410 simulator (, or Richard Cornwell’s emulator in SimH and then taking a snapshot of “core” to pre-load into the FPGA.  At that point I expect I will be able to test the CPU pretty thoroughly.  I hope and expect that will happen this year sometime.

Unfortunately, I do not have the ALDs (Automated Logic Diagrams) for the IBM 1414 I/O Synchronizers, but I do have the Instruction Logic Diagrams which should allow me to code VHDL to emulate card, tape and maybe eventually even disk functions, so those might take a while.