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VEB Robotron - Any opinions?

MCollins

MCollins

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Joined
Mar 27, 2025
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Location
Ohio
Hello everyone! Does anyone have any experience with VEB Robotron computers? As an American, I'm most knowledgeable about IBMs, Commodores, Radio-Shacks, Dells, Gateways, and others, however, I'd love to know more about ones from Eastern Europe, particularly Robotrons. If anyone has one, please tell me about it! Specs, programs, capabilities, general use, fun aspects; anything would be appreciated! Thank you!
 
Not sure what you are after. There are two main lines of PC Compatibles. A7150 - 8086 somehow compatible on DOS level and the EC1834, that is almost an XT Clone. The fun part with EC1834 is that they use an NEC7220 graphics controller to emulate a CGA compatible Graphics Card. So you have a 640x480x16 Resolution plus CGA compatibility modes.
What I find most intriguing in Eastern Europe the 8088 was never seen a real option for a CPU. Only 8086 type has been used for speedup that comes with 16-bit databus.

Here is the complete overview.
 
OLI-FIX said:
Not sure what you are after. There are two main lines of PC Compatibles. A7150 - 8086 somehow compatible on DOS level and the EC1834, that is almost an XT Clone. The fun part with EC1834 is that they use an NEC7220 graphics controller to emulate a CGA compatible Graphics Card. So you have a 640x480x16 Resolution plus CGA compatibility modes.
What I find most intriguing in Eastern Europe the 8088 was never seen a real option for a CPU. Only 8086 type has been used for speedup that comes with 16-bit databus.

Here is the complete overview.
Click to expand...
That's exactly what I'm after! It's really interesting they chose for it to be CGA compatible. It would be telly interesting how many other models Robotron made had the same controller. It's also wild they chose against using the 8088 chips. Thank you!
 
The choice of 8086 over 8088 seem straight forward. Since the maximum frequency of any CPU were limited to somewhere around 5 MHz and cycle time of a DRAM between 250ns and 450ns. The only way to get much improvement is to increase the bus size from 8 bit to 16 bit. In that sense a "16-bit" CPU would allow 2x the calculating speedup.
Our taiwanese or japanese colleagues instead choose to increase clock frequency. By 1990 8 MHz CPUs 8088 were available at low cost.
The CGA compatibility was about some registers, palette or memory layout, probably VSYNC, base on the fact that many programs access the HW directly. If you want to have some fun you may check the schematics for details:
 
OLI-FIX said:
The choice of 8086 over 8088 seem straight forward. Since the maximum frequency of any CPU were limited to somewhere around 5 MHz and cycle time of a DRAM between 250ns and 450ns. The only way to get much improvement is to increase the bus size from 8 bit to 16 bit. In that sense a "16-bit" CPU would allow 2x the calculating speedup.
Our taiwanese or japanese colleagues instead choose to increase clock frequency. By 1990 8 MHz CPUs 8088 were available at low cost.
The CGA compatibility was about some registers, palette or memory layout, probably VSYNC, base on the fact that many programs access the HW directly. If you want to have some fun you may check the schematics for details:
Click to expand...
That is true. I suppose it just seemed strange that Robotron wouldn't have chosen the 8088 since it was less expensive, even if it meant sacrificing speed since most processors cost about ten times or more than they could be produced in West Germany. I suppose the move to 16-bit with using the 8086 was probably a way to try to catch up with western comptuer development since they tried being XT compatible in the late 80s. Also thank you for the schematics! they're really interesting!
 
MCollins said:
That is true. I suppose it just seemed strange that Robotron wouldn't have chosen the 8088 since it was less expensive, even if it meant sacrificing speed since most processors cost about ten times or more than they could be produced in West Germany. I suppose the move to 16-bit with using the 8086 was probably a way to try to catch up with western comptuer development since they tried being XT compatible in the late 80s. Also thank you for the schematics! they're really interesting!
Click to expand...
Note how stuffed with RAM many of the East German 8-bit machines were. It didn't make much sense to design an 8088 machine that supported less RAM. Single RAM bank, pointless. The cost to build an 8086 was the same as the cost to build the 8088. By the time East Germany bothered with 8086 designs, the 16-bit accessory chips had fallen in price eliminating the cost savings of using 8-bit support chips. East Germany made so few computers that only a tiny bit of the world market needed to be imported to supplement whatever was manufactured internally.
 
krebizfan said:
Note how stuffed with RAM many of the East German 8-bit machines were. It didn't make much sense to design an 8088 machine that supported less RAM. Single RAM bank, pointless. The cost to build an 8086 was the same as the cost to build the 8088. By the time East Germany bothered with 8086 designs, the 16-bit accessory chips had fallen in price eliminating the cost savings of using 8-bit support chips. East Germany made so few computers that only a tiny bit of the world market needed to be imported to supplement whatever was manufactured internally.
Click to expand...
Looks like I need to hit the books more and read up more on these chips and their clones, especially Soviet and East German ones. I suppose was still thinking about the late 70s and very early I'm terms of cost when such a dramatic difference in expense still existed. Thank you for your insight! I admitted don't know as much about 80s computers as I do ones from the mid to late 90s, so this is very helpful!
 
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