On 02/08/2018 09:51 PM, Kenneth Seefried via vcf-midatlantic wrote:
Anyone have an old IGS kicking around? I've been working on my DEChub 90T1 and would like to see just how similar the two are.
I have at least one (I learned IOS on it), but have no idea where I stored it or when I'll have time to find it. I'll keep you in mind.
Yes, the IGS was a 68k-based, fixed-port (1 AUI ethernet and 1 sync serial) router. It was contemporary with the high-end AGS and midrage CGS. Ran IOS out of ROM, and upgrading required a physical ROM swap. Mine was IOS 8, but I think there was an IOS 9 update before the IGS was replaced by the c2500 series.
There were distributions of IOS 10, and possibly 11, for the IGS. I don't know if they were commercially available, but we had it at Digex. I have EPROM and flash images for 10 for the IGS/MGS/etc routers here somewhere. There was only one version of the IGS that stored its IOS image in flash, the token ring version. That was closer to being a 3000 than an IGS, but it was badged "IGS". The 3000 was an IGS with a 20MHz 68030 replacing the 16MHz 68020, and flash instead of EPROM for IOS. And the chassis paint and stickers were the later colors, and had the updated logo. The 2500 series was a technology refresh, shrink, and repackaging of the 3000, but the systems-level architecture remained largely the same. So close, in fact, that early IOS releases were the same (actually the same image files) between them. All of these are "integrated interfaces" versions of the modular CGS ("Compact"), MGS ("Medium"), and AGS ("Advanced") routers. Essentially small, medium, and large. These were all Multibus-based, but the AGS+ added the Cbus interconnect, which required a separate board, a Cbus controller to bridge it to the Multibus. I was told by a Cisco guy at the time that Cbus was an implementation of the NuBus protocol, but that may not have been correct. Cbus is about four times faster than Multibus. The Cbus slots go alongside the Multbus P1 connectors, where the card-edge P2 connectors would normally go, but used (I think) DIN 41612 connectors instead of card-edge. The CGS/MGS/AGS/AGS+ routers could be 68030- or 68040-based, depending on whether you populated it with a CSC/3 or CSC/4 CPU board. Great machines, all of them. And great memories too. -Dave -- Dave McGuire, AK4HZ New Kensington, PA