XT/IDE is great but what about if the HDD was actually an image file on a network server?
The technology for this already exists - ATA over Ethernet (ATAoE): a layer-2 protocol - there's no TCP or IP and the protocol itself is very simple, only about 10 pages. It's nothing like iSCSI (which is horrid). The server side is available on any Linux distro (for example apt-get install vblade on Ubuntu).
Because ATAoE is so simple and since we already have a comprehensive IDE BIOS (the awesome XT/IDE Universal BIOS) that has been specifically coded to allow the use of different physical layers (VL-Bus, 16-bit, 8-bit, JRIDE etc), my gut feel is that we should be able to pull together the functionality of XT/IDE but running via ATAoE and get a usable solution for XT class hardware.
So there are two possibilities:
1. To create a software solution, i.e. a boot ROM that can drive some readily available 8-bit NICs. The problem is that we'd need to embed the packet drivers into the ROM and therefore also emulate a bunch of DOS handlers to make that work; basically create a PXE in ROM. Also I'm not sure how well this could perform.
2. To build our own ISA card using a single-chip Ethernet controller like the SMSC LAN91C96. It seems that this will offload most of the work involved so should perform better, and also we can program for it directly. Of course there's a downside... it's a TQFP-100 package and expensive at nearly £20. But the chip has a reasonable buffer, will work directly with the 8-bit bus, and is 5V.
Hence, looking to open this up to the community!
The technology for this already exists - ATA over Ethernet (ATAoE): a layer-2 protocol - there's no TCP or IP and the protocol itself is very simple, only about 10 pages. It's nothing like iSCSI (which is horrid). The server side is available on any Linux distro (for example apt-get install vblade on Ubuntu).
Because ATAoE is so simple and since we already have a comprehensive IDE BIOS (the awesome XT/IDE Universal BIOS) that has been specifically coded to allow the use of different physical layers (VL-Bus, 16-bit, 8-bit, JRIDE etc), my gut feel is that we should be able to pull together the functionality of XT/IDE but running via ATAoE and get a usable solution for XT class hardware.
So there are two possibilities:
1. To create a software solution, i.e. a boot ROM that can drive some readily available 8-bit NICs. The problem is that we'd need to embed the packet drivers into the ROM and therefore also emulate a bunch of DOS handlers to make that work; basically create a PXE in ROM. Also I'm not sure how well this could perform.
2. To build our own ISA card using a single-chip Ethernet controller like the SMSC LAN91C96. It seems that this will offload most of the work involved so should perform better, and also we can program for it directly. Of course there's a downside... it's a TQFP-100 package and expensive at nearly £20. But the chip has a reasonable buffer, will work directly with the 8-bit bus, and is 5V.
Hence, looking to open this up to the community!
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