Manawyrm/ISA8019 – RTL8019-based ISA network card, NE2000-compatible
github.com
github.com
Along w/ the Snark Barker[1] that's made the rounds on Hacker News as-of-late, I recently learned about the Orpheus[2] 16-bit ISA sound card.
I've gotten some stuff from BMoW[3] for the Apple ][ line, and Individual Computers[4] for my Amiga gear. It's been a lot of fun.
Emulation is alright, but it's not a substitute for experiencing the real hardware.
[1] https://news.ycombinator.com/item?id=19006336
[2] http://orpheus-soundcard.eu/
A smaller form-factor would be more appealing. It's been a long time since I've seen one, but the card looks a bit larger than the original. More recent PCI network cards had gotten down to one main chip, plus just enough board to plug it in and fit the riser slot.
I do wonder a bit about the utility of cloning something made in the millions or at hundreds of thousands. Is there more to this project than a drop-in replacement?
Also, don't forget to make sure to flash each eeprom with different MAC address otherwise you will have some fun to figure out why you have 50% packet loss.
There is a booming business in recycled gear.
An old boss retired and started getting calls from other geezers who were getting calls from old clients (he was a CE for DEC and SGI way back).
He ended up starting a little business with maintenance contracts or subcontracts with other providers. A couple of years ago he was making a good buck and had 7-8 guys in the field.
Usually customers were really big or really small and had some ancient system that was too expensive to figure out. One utility depended on a cluster of 33Mhz PowerPC AS/400 boxes to do their billing — they paid a lot of money for best effort break fix. Another used 286 PCs for controlling elevators.
I have a Zenith/Heathkit Z-160 luggable, an 8-bit ISA bus system, which I installed an 8-bit ISA network card in. 8-bit ISA network cards are much more difficult to find than 16-bit ISA network cards but still it was only $20 on ebay.
Is there even a new x86 ISA system that you could buy today?
Though you'll find that a lot of them are single-board computers meant to interface with a bus backplane, either PC/104 (as the sibling comment notes) or... more advanced, like this thing: https://www.advantech.com/products/1-2jkn6l/pca-6028/mod_e93...
which will accept aCore i7s and 16GB of RAM, and has native ISA.
Nothing prevents you from emulating, I don't know, an Intel PRO/1000 or RTL8169 on one of these boards, or rolling your own board design from scratch. All the datasheets are out there.
But the design of this card is modern--everything is down to two ICs and a few other tiny surface mount parts that look more at home on a cellphone board than a PC ISA card from the 80's.
Compare with pictures of actual old ISA NE2000-compatible cards (eBay a good source) and I'm sure the BOM is at least 2x of this NIC.
Plus this is open source.
Take a moment to review ISA v2.01 spec[1] § 10.4:
> To minimize crosstalk between signals and bus reflections, the driver rise/fall rates must be greater than 3ns; only LS or ALS devices are allowed. Faster parts such as F and AS cannot be used to drive the bus.
If you thought it odd that normative language like this explicitly calls out tech by name, then you might have some sense of just how concerned Intel was about interoperability at the time...no thanks to wire coat hanger designers.
Also consider the language of PC/104 v2.6 spec[2] § 4.7, which is probably one of the last remaining modern platforms with native ISA bus integration:
> Whether [ac] termination is needed and where it should be located, is dependent on the specific system configuration and must be determined by the system designer.
Now consider for a moment why this language and the paragraphs that precede it exist in this independent standard. This design is a commidity peripheral that will be integrated into arbitrary systems.
Length matching literally costs nothing...but even this is apparently a "stretch goal" given the obvious fact that this design completely dismissed the normative max 2.5" stub length requirement.
So no, I disagree. For the sake of sensible SI that's too often conveniently dismissed by hobbyists, keep your wire coat hangers in the closet.
[1] https://archive.org/details/bitsavers_intelbusSpep89_3342148...
Well arguably it does cost some time yet is utterly pointless on an ISA card (unless your traces are 40 meters long I guess) there's plenty of pedantic things you could waste time on designing an ISA card