GOS has a disk cache and memory compression feature to speed up the disk load times. GOS version 95.08.13.11:54 had a relatively larger cache size, so I used this version for the benchmark.

The following is a screen dump of a benchmark utility:

total file # : 8
total byte # : 9549
total time   : 5  sec.
byte / time  : 1909.8  bytes/sec.


ready.
status

current drive # :8
fastid :on
fastopen :on
cache size :128 blocks
fastopen file size :36 files
cache hit # :52
cache missed # :78
cache success : %40
cache compress ratio : 1.25490196
free system ram :351 bytes
max. free system ram : 440 bytes

And the program is:

5 rem dataflow rate test prg.
10 cls
20 dima%(50),i,j,k,a$:i=.:j=.:k=.:ti$="000000"
21 poke56331,0:poke56330,0:poke56329,0:poke56328,0
30 reada$:ifa$="end"thengoto500
35 print"retrieving "a$;" ";
40 dummy,a%(i),a$,8:printa%(i):j=j+a%(i):i=i+1
50 goto30
99 end:run
100 data"gsb.iterate"
110 data"gsb.numofite"
120 data"gsb.testline"
130 data"gsb.datarate"
140 data"gsb.mandelrnd"
150 data"gsb.dersprog"
160 data"gsb.disker"
170 data"gsb.edit"
180 data end
499 end:run
500 t1=peek(56329)
505 print"total file # :"i
510 print"total byte # :"j
520 print"total time   :"t1" sec."
530 print"byte / time  :"j/t1" bytes/sec."
600 end:run

Here, the 'dummy' GOS command loads a file and puts its size into the given variable. And the locations 56331-56328 are the TOD clock locations. Clock starts when you poke a value to 56328 (tenth of second).

So, this test shows that the random disk speed is 1909 Bps with a 40% cache hit rate. This figure includes the directory lookup of the files, the random seeks (which are eliminated by 40%) and the decompressions of the blocks. Not bad for a 19 years old cache I think.

İlker Fıçıcılar
31.07.2014

Keywords: GOS, Commodore 64, Operating System, Disk Speed, Benchmark