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Wilson Mines Co.

   •  6502 (& related) microprocessor articles, primers, tutorials, and links
   •  electronics modules for hobbyists, for easing the construction of home-made computers
   •  HP-41 calculator/computer links (approx 50)

The first module is a 32Mb 4Mx8 5V 10ns SRAM module.  Data sheet here.  Email me at wilsonmines@dslextreme.com to buy.  The module is 2.3" long, and is available with 90° pins (shown first, and it makes the module stand perpendicular to the mother board) or straight (shown second, and which puts it parallel to the mother board).

WM-1 32Mb 4Mx8 10ns 5V SRAM module, 90° pins WM-1 32Mb 4Mx8 10ns 5V SRAM module, straight pins SBC-4 with WM-1 memory module

This is the densest, fastest 5V SRAM module that I know of, and its pin header makes it hobbyist-friendly.  When fully populated, it has 64 times as much RAM as the Commodore 64 did, and 32 times as much as the original Mac did.  Being SRAM, it can be battery-backed, and is free of the complications of DRAM management requirements.  There's more discussion of it on the forum here.  Daryl Rictor's SBC-4 computer which he sells (pictured above) uses it.  I can provide the sockets too, both in soldertail and in wire-wrap.  The price has gone up and down (mostly down) with the price of the ICs, but probably won't get any lower now.  I get the ICs in quantity from a Cypress distributor for about a third of what you would probably have to pay for just a few.  A fully loaded module is $69+postage (+sales tax if going to a CA address).  Partially loaded modules are available for less.


Next is a tiny SPI-10 flash-memory module, again very hobbyist-friendly.  The board is made for 25VF016, 25VF032, 26VF032, 25VF064, 26VF064, or any other SPI flash ICs in a normal or wide SO-8 package with the same pinout.  (The 32's are four megabytes, and the 64's are eight.)  I'll post a data sheet soon.  Here in the picture are:

WM-2 SPI-10 flash module

Granted, 4MB or 8MB is not much storage compared to what comes in CF of SD cards; but it's quite a bit for a 6502 system where you won't be storing videos or doing photo editing and probably won't even be listening to music on it.  It's much easier to work with in terms of writing your own software drivers, and also cheaper than the standard consumer-electronics memory cards.  You can make your own file system, or use them with no file system at all (as in my first use of one, for recording audio, in a loop).

I have not yet decided how to price these.  The price of the bare board will be well below that of the IC, probably even including shipping if it's to U.S. addresses.  As for selling pre-assembled units:  The amount of assembly time required is fine for small quantities for personal use, but if I assemble them for others, I'd probably need to charge more than they will want to pay; so I might just sell the bare boards, with an exception for the few customers who can't see well enough to assemble one, or have other limitations.  As with any boards, a large-enough order would justify the set-up cost for automated assembly, reducing the price of completed modules.  Email me to buy.


Also available:  1Mx8 EPROM pairs (27C801 in 32-pin windowed DIP) pre-programmed with the large look-up tables for hyper-fast, accurate 16-bit math on any 8-bit computer.  See the articles linked for info.  I have some that were graciously donated and programmed by Tony Gonzalez (Nightmaretony, an esteemed member of the 6502.org forum, who unfortunately died with cancer in his 40's on 11/4/12), so until those are gone, your cost is only the shipping cost.  (If you want to do your own, or load the tables into RAM, the Intel Hex files are available at the link.)


Now that I've hooked up with a PCB manufacturer that is very inexpensive for small quantities, I expect to introduce more modules at a quicker pace in the near future.  Goals for a home-made computer tend to quickly become too lofty to carry them out in your lifetime, or change faster than you can build.  It helps to have various sections ready-made.  The SRAM module above integrates up to eight fast SMT 512Kx8 5V SRAMs and the bypass capacitors on a small board with parts on both sides and a dual-row socket of 46 pins on .100" centers which is perfect for breadboarding (although if you breadboard, I do recommend using breadboard with a ground plane like Twin Industries,' 8100 or 8200 series for this high-performance module).  This is not solderless breadboard, but the type used for wire-wrapping.  I can provide the sockets.


There's a brief write-up on how I got into home-made workbench computers, microcontrollers, and automated test equipment, with links, in my "Introduce Yourself" post, the first one in the topic.  I am very active on that forum, and also have some articles on 6502.org.  I have a similar write-up here on how I got into HP calculators as equipment controllers on the workbench, which influenced my own home-made workbench computer designs.

Many more articles, plus show-and-tell of my own projects, are planned for this website.


For 250 links to materials on:

click here.

added 10/1/15:  6502 stacks treatise  6502 Stacks: More than you thought!  (actually a set of 19 articles plus appendices, covering many aspects)
added 7/15/15:  NMOS v. CMOS 6502 differences
added 6/9/15:    Assembly Language:  Still Relevant Today  (article, not tutorial)
added 2/17/15   6502 interrupts primer.  I put it on 6502.org 12 years earlier, and it will remain there too; but it's much easier to edit on my own site.
added 5/16/14:  simple methods for multitasking without a multitasking OS
added 7/28/12:  program structures in 65c02 (and PIC16) assembly, through macros
added 6/25/12:  16-Bit scaled-integer math, hyper-fast and accurate, with large look-up tables (provided)  Plus: The unexpected power of scaled-integer math
added 4/27/12:  6502 PRIMER: Building your own 6502 computer (actually a set of 22 articles covering many aspects, some relating equally well to other computers too)
added 4/5/12:    RS-232 primer



This website gets over 600 page downloads per day, over 1800 files per day.  The most popular section is the 6502 primer, followed by the section on 16-bit scaled-integer math and the large look-up tables.  Many thanks to Andy Werner ("handyandy" on the 6502.org forum) who proofread virtually my entire site!

page last updated Dec 2, 2016               contact: Garth Wilson, wilsonmines@dslextreme.com (southern California)
domain reserved 2/18/12      © Wilson Mines Co. 2012-2016