Post AYValUY2sRNhAsQBsm by darryl_ramm@hachyderm.io
 (DIR) More posts by darryl_ramm@hachyderm.io
 (DIR) Post #AYValRMEjt9XHNsDYm by darryl_ramm@hachyderm.io
       2023-08-08T03:32:21Z
       
       0 likes, 0 repeats
       
       At the Vintage Computer Festival West I was helping show HP 80 Series computers. The things that got people’s attention was driving a HP-GL pen plotter. Or this wireframe Utah teapot on the display. This is a very slow computer, but folks would ask…… “can it rotate?” uh definitely not… ”how long does it take to render that 3D” uh it’s not 3D and it takes *minutes* to draw those 2D lines.… “Can you show me how long drawing that takes?”… OK but it is really slow… (gets bored and leaves…)
       
 (DIR) Post #AYValUY2sRNhAsQBsm by darryl_ramm@hachyderm.io
       2023-08-08T03:40:17Z
       
       1 likes, 0 repeats
       
       Why is a series 80 so slow? It is a HP ”Capricorn” microprocessor designed by calculator folks…o 8-bit CPU in NMOSo 24pin DIPo 625 KHz clock, yes kHzo CPU is microcodedo 8-bit data/16-bit address multiplexed 8-bit buso All BCD math (except address)o No divide or multiply instructions, you get BCD add, subtract and left/right shifto Graphics is byte at a time shuffled through an 8-bit IO register into part of external 4 KB video memoryStill interesting to HP calculator nerds like me.