you could do a swap tick on the ver first model psx's, it involved jamming the lid switch with some bluetac then booting with an original disc, waiting for it to slow down for the second time and ripping it out whilst spinning and jamming in your copy, it did work but its realy not wise, if you have a psx before the 9000 series then use one of the ar type chip carts if you have a 9000 or ps1 then its a boot disc or a chip, honestly i'd go for the chip, its cheap, easy and works reliably and you get to close your playstation lid (you cant do that with a ps1 if using a bootdisc)