The reason I did it was because I'd been asked by an Amsterdam cultural center (the meervaart) to show the people living near it during a presentation how the situation would change upon expanding the meervaart.
The director (Han Hogeland) had asked me to do the presentation in exchange for - no laughing please - an old French car that I'd wanted to buy of him (Citroen DS).
This made me very motivated to make it work, only my 16 Mhz 386/387 combo really wasn't fast enough to make it work and I didn't have enough dough for a weitek.
So, from desperation this little hack was born. After I found out that it worked (much to my surprise, actually, testing on 20 MHz) I went to a friend who had a computer store and went through several trays of 387's before finding one that would still run at 40 Mhz, and with a large cooling element attached it even stayed reasonably cool (no fan).
The hardest part really was to cut the line on the mb without damage to other lines (this was a multi layer board), eventually I traced the line to a so called 'via' where I could scratch out the connection topside and use the remains of the via to connect the xtal oscillator (in a socket so I could try various frequencies).
The whole thing worked pretty good even if it looked absolutely terrible (imagine an ic socket piggy backed on top of a ttl IC for power and ground, then a wire running to a via next to a severed trace).
It's a pity I didn't make any pictures of the whole thing, I do still have the aerial photographs we bought of the cartographic institution that were digitized to get the layout in to the software, then extrusion by estimated building height created a fairly realistic view of the area.
The shading was quite primitive, framerate about 2-3 frames / second depending on the amount of stuff in the field of view. The graphics board was a 3x5 bits 512x512 pixels affair whose name escapes me atm.
The director (Han Hogeland) had asked me to do the presentation in exchange for - no laughing please - an old French car that I'd wanted to buy of him (Citroen DS).
This made me very motivated to make it work, only my 16 Mhz 386/387 combo really wasn't fast enough to make it work and I didn't have enough dough for a weitek.
So, from desperation this little hack was born. After I found out that it worked (much to my surprise, actually, testing on 20 MHz) I went to a friend who had a computer store and went through several trays of 387's before finding one that would still run at 40 Mhz, and with a large cooling element attached it even stayed reasonably cool (no fan).
The hardest part really was to cut the line on the mb without damage to other lines (this was a multi layer board), eventually I traced the line to a so called 'via' where I could scratch out the connection topside and use the remains of the via to connect the xtal oscillator (in a socket so I could try various frequencies).
The whole thing worked pretty good even if it looked absolutely terrible (imagine an ic socket piggy backed on top of a ttl IC for power and ground, then a wire running to a via next to a severed trace).
It's a pity I didn't make any pictures of the whole thing, I do still have the aerial photographs we bought of the cartographic institution that were digitized to get the layout in to the software, then extrusion by estimated building height created a fairly realistic view of the area.
The shading was quite primitive, framerate about 2-3 frames / second depending on the amount of stuff in the field of view. The graphics board was a 3x5 bits 512x512 pixels affair whose name escapes me atm.
And I got the car :)